Merge "add rgtc extension support" am: 7d956957b4 am: 2394077695 am: 700b43e6e0

Original change: https://android-review.googlesource.com/c/device/generic/goldfish-opengl/+/1945417

Change-Id: Ibd0e9e2cb1ec746ac5af7c25c9901d993ac43a1c