Explicitly add the theme manager's AID to fs config

SELinux failed to set the theme manager's context since the
app has a fixed non-user ID, and it didn't map to a pseudo-username.

Change-Id: I287dc0dd02abc164fe22e14c9f3f505c3dcb938d

Conflicts:
	include/private/android_filesystem_config.h
toolbox: Add levelFromUid categorization support to restorecon

This is necessary for the app data relabeling on migrated devices
to include the proper app context. Freshly installed apps get this
done automagically, as do newly created files.

Change-Id: If7421dac01c6ae8bd78e66f71e69298ed850a7ab