support aidl bp2build changes

- Allowlist an aidl module by package, not name (to support a small
  module name change)
- Implement some unit test framework changes which facilitate better
  aidl bp2build testing
- Support a convenience function to add a load hook for registering a
  module as "has a bazel definition of a given target name"

Bug: 301676937
Test: m bp2build, verified the aidl target was generated before/after
this CL.
Test: Presubmits
Test: Ran bp2build progress and ensured that aidl_interface targets
under frameworks/ continued to appear converted

Change-Id: I62412057d6f61a2ce2bc39488c75af793eb14c94