android_emulator.md: Update to mention -read-only flag. Remove virtualgl

-read-only is an awesome new feature!

I haven't found virtualgl to be necessary any more.

Bug: 965498
Change-Id: Ief49d15d4cf8f8c0d3d8a968d0ffdf3703a74a46
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1621628
Auto-Submit: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Peter Wen <wnwen@chromium.org>
Commit-Queue: Peter Wen <wnwen@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#662329}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: c8f2703db09860ffb8e570259ac56193f1cd7a0d
2 files changed