Fixes for running on the iOS simulator.

* Disable pixel formats not supported by Metal on the simulator
* Work around invalid sample count value in GLES

Change-Id: I711c3d906ef1c0a467dfc1fb5d36eac2277e7ae0
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/282270
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: Jim Van Verth <jvanverth@google.com>
2 files changed