google-cloud-java: libraries API path in config but not generated

[zhumin8]

Observed managed-identities and os-login, one of the API path currently configured in generation_config.yaml but is not in generated code.
Investigate and decide on action. Possibly remove extra config for the sake of migration to reflect reality. Add v1beta path config if needed after migration is done.

java-managed-identities/
Configured
- path: google/cloud/managedidentities/v1
- path: google/cloud/managedidentities/v1beta1

But only v1 code in module.

java-os-login/
Configured
- path: google/cloud/oslogin/v1
- path: google/cloud/oslogin/v1beta
But only has v1 code.

Also filed googleapis/google-cloud-java#12736

[zhumin8]

Both of these libraries are added to the generation_config.yaml as part of initial migration to hermetic build: googleapis/google-cloud-java@14b7346
They are not new libraries.

[zhumin8]

Proved my guess in googleapis/google-cloud-java#12830, it produced the missing v1beta modules and main client library code. There are some ci failures, but looks unrelated.
@blakeli0 do we want to add these to code as in #12830 or do the reverse and remove the api path from config?

[blakeli0]

Thanks Min for the catch! Considering they are v1beta1, do we need to generate them? Are they generated in other languages? Can we remove them from generation_config.yaml?