chore(deps): upgrade gapic-generator-java to 2.8.0 and update gax-java to 2.18.1 (#1886)

- [ ] Regenerate this pull request now.

PiperOrigin-RevId: 450543911

Source-Link: googleapis/googleapis@5528344

Source-Link: https://github.com/googleapis/googleapis-gen/commit/9f6775cab1958982b88967a43e5e806af0f135db
Copy-Tag: eyJwIjoiLmdpdGh1Yi8uT3dsQm90LnlhbWwiLCJoIjoiOWY2Nzc1Y2FiMTk1ODk4MmI4ODk2N2E0M2U1ZTgwNmFmMGYxMzVkYiJ9

Author: gcf-owl-bot[bot]

google-cloud-spanner/src/main/java/com/google/cloud/spanner/admin/database/v1/DatabaseAdminClient.java

@@ -18,7 +18,6 @@
 
 import com.google.api.core.ApiFuture;
 import com.google.api.core.ApiFutures;
-import com.google.api.core.BetaApi;
 import com.google.api.gax.core.BackgroundResource;
 import com.google.api.gax.longrunning.OperationFuture;
 import com.google.api.gax.paging.AbstractFixedSizeCollection;
@@ -170,7 +169,6 @@ public static final DatabaseAdminClient create(DatabaseAdminSettings settings)
    * Constructs an instance of DatabaseAdminClient, using the given stub for making calls. This is
    * for advanced usage - prefer using create(DatabaseAdminSettings).
    */
-  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
   public static final DatabaseAdminClient create(DatabaseAdminStub stub) {
     return new DatabaseAdminClient(stub);
   }
@@ -186,7 +184,6 @@ protected DatabaseAdminClient(DatabaseAdminSettings settings) throws IOException
     this.operationsClient = OperationsClient.create(this.stub.getOperationsStub());
   }
 
-  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
   protected DatabaseAdminClient(DatabaseAdminStub stub) {
     this.settings = null;
     this.stub = stub;
@@ -197,7 +194,6 @@ public final DatabaseAdminSettings getSettings() {
     return settings;
   }
 
-  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
   public DatabaseAdminStub getStub() {
     return stub;
   }

google-cloud-spanner/src/main/java/com/google/cloud/spanner/admin/database/v1/stub/DatabaseAdminStubSettings.java

@@ -541,7 +541,6 @@ public UnaryCallSettings<RestoreDatabaseRequest, Operation> restoreDatabaseSetti
     return listBackupOperationsSettings;
   }
 
-  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
   public DatabaseAdminStub createStub() throws IOException {
     if (getTransportChannelProvider()
         .getTransportName()

google-cloud-spanner/src/main/java/com/google/cloud/spanner/admin/instance/v1/InstanceAdminClient.java

@@ -18,7 +18,6 @@
 
 import com.google.api.core.ApiFuture;
 import com.google.api.core.ApiFutures;
-import com.google.api.core.BetaApi;
 import com.google.api.gax.core.BackgroundResource;
 import com.google.api.gax.longrunning.OperationFuture;
 import com.google.api.gax.paging.AbstractFixedSizeCollection;
@@ -167,7 +166,6 @@ public static final InstanceAdminClient create(InstanceAdminSettings settings)
    * Constructs an instance of InstanceAdminClient, using the given stub for making calls. This is
    * for advanced usage - prefer using create(InstanceAdminSettings).
    */
-  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
   public static final InstanceAdminClient create(InstanceAdminStub stub) {
     return new InstanceAdminClient(stub);
   }
@@ -183,7 +181,6 @@ protected InstanceAdminClient(InstanceAdminSettings settings) throws IOException
     this.operationsClient = OperationsClient.create(this.stub.getOperationsStub());
   }
 
-  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
   protected InstanceAdminClient(InstanceAdminStub stub) {
     this.settings = null;
     this.stub = stub;
@@ -194,7 +191,6 @@ public final InstanceAdminSettings getSettings() {
     return settings;
   }
 
-  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
   public InstanceAdminStub getStub() {
     return stub;
   }

google-cloud-spanner/src/main/java/com/google/cloud/spanner/admin/instance/v1/stub/InstanceAdminStubSettings.java

@@ -318,7 +318,6 @@ public UnaryCallSettings<GetIamPolicyRequest, Policy> getIamPolicySettings() {
     return testIamPermissionsSettings;
   }
 
-  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
   public InstanceAdminStub createStub() throws IOException {
     if (getTransportChannelProvider()
         .getTransportName()

google-cloud-spanner/src/main/java/com/google/cloud/spanner/v1/SpannerClient.java

@@ -18,7 +18,6 @@
 
 import com.google.api.core.ApiFuture;
 import com.google.api.core.ApiFutures;
-import com.google.api.core.BetaApi;
 import com.google.api.gax.core.BackgroundResource;
 import com.google.api.gax.paging.AbstractFixedSizeCollection;
 import com.google.api.gax.paging.AbstractPage;
@@ -152,7 +151,6 @@ public static final SpannerClient create(SpannerSettings settings) throws IOExce
    * Constructs an instance of SpannerClient, using the given stub for making calls. This is for
    * advanced usage - prefer using create(SpannerSettings).
    */
-  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
   public static final SpannerClient create(SpannerStub stub) {
     return new SpannerClient(stub);
   }
@@ -166,7 +164,6 @@ protected SpannerClient(SpannerSettings settings) throws IOException {
     this.stub = ((SpannerStubSettings) settings.getStubSettings()).createStub();
   }
 
-  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
   protected SpannerClient(SpannerStub stub) {
     this.settings = null;
     this.stub = stub;
@@ -176,7 +173,6 @@ public final SpannerSettings getSettings() {
     return settings;
   }
 
-  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
   public SpannerStub getStub() {
     return stub;
   }

google-cloud-spanner/src/main/java/com/google/cloud/spanner/v1/stub/SpannerStubSettings.java

@@ -268,7 +268,6 @@ public UnaryCallSettings<PartitionReadRequest, PartitionResponse> partitionReadS
     return partitionReadSettings;
   }
 
-  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
   public SpannerStub createStub() throws IOException {
     if (getTransportChannelProvider()
         .getTransportName()