The READ_FRAMEBUFFER_BINDING dirty bit sync was missing from copy image
functions.  In the Vulkan backend, a cached value for the current read
framebuffer was used to determine if the copy should flip in Y, and that
cached value was out of date.

Bug: angleproject:3723
Change-Id: I10e8a276a42c28fbedc9939f653a5a1f4a14e87b
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1715483Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Mohan Maiya <m.maiya@samsung.com>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>