ObsoleteApi: `getDefualtEndpoint()` in the generated ServiceStubSettings

[lqiu96]

Changes:

• The getDefaultEndpoint() will be marked with @ObsoleteApi annotation with the intention of removing it in a future major version bump.
• The generated ServiceStubSetting classes will no longer be passing the a default endpoint via the getDefaultEndpoint() method.

Example of the generated endpoints:

• AccessApproval
• Redis

What's Changing (Behavior/ Code)

There are no changes required on the user's end. The client will automatically determine the endpoint and the default value used remains {service}.googleapis.com. If there are user configurations for the endpoint, the configured value will be used.

How to set a custom endpoint

See this as an example of how to configure the endpoint