Add enforcement parameter to RequiresFeature

* Allows for a broader range of enforcement checks
* Designed to match androix so that it can be easily slotted into
Android Studio lint checks

Test: Built
Bug: 173735303
Change-Id: Ia4cc8be8fdccbdeeecee956e4ccf02bda6d91845
Merged-In: Ia4cc8be8fdccbdeeecee956e4ccf02bda6d91845