GL: Clamp uniform array access on Android and AMD devices. Chrome used to clamp it everywhere but in practice it is only needed on these devices. TEST=conformance/uniforms/out-of-bounds-uniform-array-access.html Change-Id: Idffe84023f8b27733bfda209edd59bbb220b5c0c Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1680054 Reviewed-by: Jonah Ryan-Davis <jonahr@google.com> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Geoff Lang <geofflang@chromium.org>