Add a Method to Revoke DefaultGrant Permissions

Runtime permissions grants for system-bound
services should be revoked when no longer needed.
This ensures that in cases where say, a package
is needed while a user is using a certain cellular
provider, that package will lose its privileges
if the user changes providers.

Bug: 66955045
Test: compilation (still WIP)
Change-Id: I8dc2dd719f3b4af83ebb2b2f4a128f267b26fd91