The CL crrev/c/2551541 causes intermittent Bot failure. I believe the
problem is that from ContextVk::onMakeCurrent call stack, the object
state may not in sync or even not completely specified. So instead of
accessing fbo state object here to update mGraphicsPipelineDesc, we
should insert dirty bit and let state validation code to handle it.

Bug: b/175157604
Change-Id: I5f6b9fd901cc4187068f6161bd12836c8bbf8e87
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2580914
Commit-Queue: Ian Elliott <ianelliott@google.com>
Commit-Queue: Charlie Lao <cclao@google.com>
Reviewed-by: Ian Elliott <ianelliott@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>