Remove support: libfeature_support_angle.so

Remove support for ANGLE's libfeature_support_angle.so.

This also removes all of the logic related to checking the rules file,
since libfeature_support_angle.so is what parsed the JSON rules file.

Bug: b/187342779
Bug: b/184757175
Test: make and manual verification ANGLE is loaded
Change-Id: I3c52b07eb262f83f8e860584790ac058de58466a
Merged-In: I3c52b07eb262f83f8e860584790ac058de58466a