Merge PR #382: Update gcp-resources module to follow style guide

Author: trask

gcp-resources/src/main/java/io/opentelemetry/contrib/gcp/resource/GCPResourceProvider.java

@@ -62,9 +62,10 @@
 import java.util.logging.Logger;
 
 @SuppressWarnings("MemberName")
-public class GCPResourceProvider implements ConditionalResourceProvider {
+public final class GCPResourceProvider implements ConditionalResourceProvider {
 
   private static final Logger LOGGER = Logger.getLogger(GCPResourceProvider.class.getSimpleName());
+
   private final GCPPlatformDetector detector;
 
   // for testing only

gcp-resources/src/main/java/io/opentelemetry/contrib/gcp/resource/IncubatingAttributes.java

@@ -13,8 +13,6 @@
  */
 class IncubatingAttributes {
 
-  private IncubatingAttributes() {}
-
   public static final AttributeKey<String> CLOUD_ACCOUNT_ID =
       AttributeKey.stringKey("cloud.account.id");
   public static final AttributeKey<String> CLOUD_AVAILABILITY_ZONE =
@@ -26,14 +24,15 @@ private IncubatingAttributes() {}
   public static final AttributeKey<String> CLOUD_REGION = AttributeKey.stringKey("cloud.region");
 
   public static final class CloudPlatformIncubatingValues {
-    private CloudPlatformIncubatingValues() {}
 
     public static final String GCP_COMPUTE_ENGINE = "gcp_compute_engine";
     public static final String GCP_CLOUD_RUN = "gcp_cloud_run";
     public static final String GCP_KUBERNETES_ENGINE = "gcp_kubernetes_engine";
     public static final String GCP_CLOUD_FUNCTIONS = "gcp_cloud_functions";
     public static final String GCP_APP_ENGINE = "gcp_app_engine";
     public static final String GCP = "gcp";
+
+    private CloudPlatformIncubatingValues() {}
   }
 
   public static final AttributeKey<String> FAAS_INSTANCE = AttributeKey.stringKey("faas.instance");
@@ -56,4 +55,6 @@ private CloudPlatformIncubatingValues() {}
 
   public static final AttributeKey<String> K8S_CLUSTER_NAME =
       AttributeKey.stringKey("k8s.cluster.name");
+
+  private IncubatingAttributes() {}
 }