chore(spanner): fix resource cleanup

Author: harshachinta

google-cloud-spanner/src/main/java/com/google/cloud/spanner/TransactionManagerImpl.java

@@ -80,6 +80,12 @@ public void commit() {
     } catch (SpannerException e2) {
       txnState = TransactionState.COMMIT_FAILED;
       throw e2;
+    } finally {
+      // At this point, if the TransactionState is not ABORTED, then the transaction has reached a terminal state.
+      // We can safely call close() to release resources.
+      if (getState() != TransactionState.ABORTED) {
+        close();
+      }
     }
   }
 
@@ -92,6 +98,9 @@ public void rollback() {
       txn.rollback();
     } finally {
       txnState = TransactionState.ROLLED_BACK;
+      // At this point, the TransactionState is ROLLED_BACK which is a terminal state.
+      // We can safely call close() to release resources.
+      close();
     }
   }
 

google-cloud-spanner/src/test/java/com/google/cloud/spanner/connection/OpenTelemetryTracingTest.java

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/*
+
 package com.google.cloud.spanner.connection;
 
 import static com.google.cloud.spanner.connection.Repeat.twice;
@@ -679,4 +679,3 @@ private void addUpdateDdlResponse() {
             .build());
   }
 }
-*/