[res] Add a feature flag for android resources RRO fix

RROs targeting 'android' currently can't be enabled-disabled
dynamically as Framework resources have no overlayable
definition. This is a flag making it possible for the apps with
the corresponding permission

Bug: 364035303
Test: build
Flag: EXEMPT adds a new flag
Change-Id: Iadd9195a7dff878f9a399e5fa6e8c8bd4421a985