Updating framework/opengl to support OpenGL ES 3.2

- Updated src_util.py to download appropriate gl.xml from Khronos.
- Dropped EXT/KHR suffix in certain function names
- Context wrapper is no longer created if native context fails to be created
Change-Id: I3b93c70ec779b7b0664925b6c57dcf16f1e8610d
44 files changed