Add pixel local storage tests for all supported formats Bug: angleproject:7279 Change-Id: I92728112f243cccf4e4ab2c5f4c096dcc0536fc2 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3654266 Commit-Queue: Geoff Lang <geofflang@chromium.org> Reviewed-by: Kenneth Russell <kbr@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>