Add extra compat change overriding methods.

This CL adds two new methods to the IPlatformCompat binder interface for
toggling multiple compat changes at once, and for clearing all the
overrides for a given package name.

Bug: 140367850
Test: http://aosp/1113771
Change-Id: I02d08d76e42da308856408dadc2c8c73c7ff20d1