Right now we are making this calls multiple times as we loop through
each shader stage. Qualcomm performance validation layer warns about
this. This change will aggregate the calls into one call per dispatch.

Bug: b/158787299
Change-Id: I48aa3752f708c26ffbca2fb7947cb8bbc0f76dcd
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2243321
Commit-Queue: Charlie Lao <cclao@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com>
Reviewed-by: Tim Van Patten <timvp@google.com>