API: Make implicit APIs from type usage explicit

API stubs generation implicitly made any types used by an API also part
of that API. This has caused DeviceIdAttestationException and
ImsFeature.Capabilities to become implicit APIs, so they are added to
the API files.

After this, using non-API types in APIs will become an error to prevent
implicit APIs occuring in the future.

Bug: 119556446
Test: METALAVA_PREPEND_ARGS="--error ReferencesHidden" make
Change-Id: I5fe4f20502b8d4e287b28e9f07139456d4191e22