Revert "libbinder: remove __ANDROID_APEX__ stability diff"

This reverts commit e9441bcf32c04901807748bde85f16444464eb91.

Reason for revert: b/180559880#comment7
Bug: 179906909

Change-Id: I04472d3bbe97c9c42df74c10ce87c176fa7098dd
4 files changed