chore(deps): upgrade gapic-generator-java to 2.8.0 and update gax-jav…

…a to 2.18.1 (#124)

- [ ] 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

java-bigquerymigration/google-cloud-bigquerymigration/src/main/java/com/google/cloud/bigquery/migration/v2/MigrationServiceClient.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;
@@ -128,7 +127,6 @@ public static final MigrationServiceClient create(MigrationServiceSettings setti
    * Constructs an instance of MigrationServiceClient, using the given stub for making calls. This
    * is for advanced usage - prefer using create(MigrationServiceSettings).
    */
-  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
   public static final MigrationServiceClient create(MigrationServiceStub stub) {
     return new MigrationServiceClient(stub);
   }
@@ -143,7 +141,6 @@ protected MigrationServiceClient(MigrationServiceSettings settings) throws IOExc
     this.stub = ((MigrationServiceStubSettings) settings.getStubSettings()).createStub();
   }
 
-  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
   protected MigrationServiceClient(MigrationServiceStub stub) {
     this.settings = null;
     this.stub = stub;
@@ -153,7 +150,6 @@ public final MigrationServiceSettings getSettings() {
     return settings;
   }
 
-  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
   public MigrationServiceStub getStub() {
     return stub;
   }

java-bigquerymigration/google-cloud-bigquerymigration/src/main/java/com/google/cloud/bigquery/migration/v2/stub/MigrationServiceStubSettings.java

@@ -306,7 +306,6 @@ public UnaryCallSettings<StartMigrationWorkflowRequest, Empty> startMigrationWor
     return listMigrationSubtasksSettings;
   }
 
-  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
   public MigrationServiceStub createStub() throws IOException {
     if (getTransportChannelProvider()
         .getTransportName()

java-bigquerymigration/google-cloud-bigquerymigration/src/main/java/com/google/cloud/bigquery/migration/v2alpha/MigrationServiceClient.java

@@ -129,7 +129,6 @@ public static final MigrationServiceClient create(MigrationServiceSettings setti
    * Constructs an instance of MigrationServiceClient, using the given stub for making calls. This
    * is for advanced usage - prefer using create(MigrationServiceSettings).
    */
-  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
   public static final MigrationServiceClient create(MigrationServiceStub stub) {
     return new MigrationServiceClient(stub);
   }
@@ -144,7 +143,6 @@ protected MigrationServiceClient(MigrationServiceSettings settings) throws IOExc
     this.stub = ((MigrationServiceStubSettings) settings.getStubSettings()).createStub();
   }
 
-  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
   protected MigrationServiceClient(MigrationServiceStub stub) {
     this.settings = null;
     this.stub = stub;
@@ -154,7 +152,6 @@ public final MigrationServiceSettings getSettings() {
     return settings;
   }
 
-  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
   public MigrationServiceStub getStub() {
     return stub;
   }

java-bigquerymigration/google-cloud-bigquerymigration/src/main/java/com/google/cloud/bigquery/migration/v2alpha/stub/MigrationServiceStubSettings.java

@@ -307,7 +307,6 @@ public UnaryCallSettings<StartMigrationWorkflowRequest, Empty> startMigrationWor
     return listMigrationSubtasksSettings;
   }
 
-  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
   public MigrationServiceStub createStub() throws IOException {
     if (getTransportChannelProvider()
         .getTransportName()