These internal repos can hold confidential code. Also updates the GLES
1.0 conformance test configuration to pull data from angle-internal.

Bug: angleproject:3621
Change-Id: Ifb9d2a5014b0827a078cfdc85fb20c5f5335204f
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1679992Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>