Add APEX module for permission.

We need an APEX module for permission to reliably roll back runtime
permission state, specifically, platform runtime-permissions.xml will
be moved into the data directory of this APEX and be rolled back when
PermissionController is rolled back.

Bug: 136503238
Test: build
Change-Id: I93166f8dc4783bd09afa6be19a302fb0c2decd0d