Optional interceptors in @GrpcService annotation

Hi!
I'm trying to use this starter and I have next problem.
I have a ServerInterceptor, that depends on other optional bean (wich enabled through configuration).
I need that interceptor only for one service, not global (for global it is easy make with ConditionalOnBean).

Maybe it will be good to add some property (e.g. "required") to @GrpcService annotation to allow to specify optional interceptors? And if there are no bean in app context, then don't fail with error, but just not register it.
Now as I understand, I can do this only manually register service through GrpcServerConfigurer.

Start by tracing how @GrpcService discovers and registers ServerInterceptor beans, then compare that path with the manually mentioned GrpcServerConfigurer approach. Check how an interceptor depending on an optional bean behaves when that bean is absent. Done should include the requested optional-registration behavior and tests covering both bean-present and bean-absent cases.

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