Merge "Represent hidden classes' subclass definitions in partial signature...

Merge "Represent hidden classes' subclass definitions in partial signature files" into main am: 8403ff76

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2700353



Change-Id: If6297d9be5e304689a0186423cdab1df5124ab09
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>