Vulkan: Check program fetch status when switching framebuffers Before this patch, we only checked whether to update the framebuffer fetch status when the program changes. We also need to check when the framebuffer itself changes. Test: FramebufferFetchES31.FramebufferMixedFetchTest Bug: angleproject:6893 Change-Id: I92ff1f30dfb3f17aee362e5931fc4c94d18142ba Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3418842 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Cody Northrop <cnorthrop@google.com>