generator: Consider removing @BetaApi from clients' LRO surface

[burkedavison]

1. Client stub settings --> Nested Builder Getter Methods

   • Example: https://github.com/googleapis/google-cloud-java/blob/880604fb2cd41d32401ed7d7a6ead2e1a5ca0b22/java-compute/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InterconnectAttachmentsStubSettings.java#L761
   • Generation logic:

     sdk-platform-java/gapic-generator-java/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceStubSettingsClassComposer.java

     Line 1984 in decd7f6

     .setType(FIXED_TYPESTORE.get("BetaApi"))

2. Client methods

   • Example: https://github.com/googleapis/google-cloud-java/blob/880604fb2cd41d32401ed7d7a6ead2e1a5ca0b22/java-compute/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/InterconnectAttachmentsClient.java#L395-L400
   • Generation logic:

     sdk-platform-java/gapic-generator-java/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceClientClassComposer.java

     Line 782 in decd7f6

     "The surface for long-running operations is not stable yet and may change in the"

3. LRO client getters:

   • Example: Unknown
   • Generation logic:

     sdk-platform-java/gapic-generator-java/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceStubClassComposer.java

     Line 238 in decd7f6

     ImmutableList.of(AnnotationNode.withType(typeStore.get("BetaApi"))),

4. HTTP JSON Service Callable Factory

   • Example: https://github.com/googleapis/google-cloud-java/blob/880604fb2cd41d32401ed7d7a6ead2e1a5ca0b22/java-compute/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/HttpJsonInterconnectAttachmentsCallableFactory.java#L43
   • Generation logic:

     sdk-platform-java/gapic-generator-java/src/main/java/com/google/api/generator/gapic/composer/rest/HttpJsonServiceCallableFactoryClassComposer.java

     Line 67 in decd7f6

     annotations.add(AnnotationNode.withType(typeStore.get("BetaApi")));

5. HTTP JSON Service Callable Factory --> Operation Callable Method

   • Example: https://github.com/googleapis/google-cloud-java/blob/880604fb2cd41d32401ed7d7a6ead2e1a5ca0b22/java-compute/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/HttpJsonInterconnectAttachmentsCallableFactory.java#L75-L79
   • Generation logic:

     sdk-platform-java/gapic-generator-java/src/main/java/com/google/api/generator/gapic/composer/rest/HttpJsonServiceCallableFactoryClassComposer.java

     Line 113 in decd7f6

     typeStore.get("BetaApi"),