Don't assume rendering complete before buffer latch
Don't assume rendering complete before buffer latch

It's valid for the buffer to latch before rendering is completed, and
this is causing intermittent failures.

Bug: b/69981429

Test: --deqp-case=dEQP-EGL*get_frame_timestamps*

(cherry picked from commit 9e0214cf61df1109927f8f23dd5749735057eb30)

Change-Id: Ia9f1d0e4ffa7f3e16a46fc4566157a651d1b0601

googlestadia/VK-GL-CTS,KhronosGroup/VK-GL-CTS,googlestadia/VK-GL-CTS,googlestadia/VK-GL-CTS,KhronosGroup/Vulkan-CTS,KhronosGroup/Vulkan-CTS,KhronosGroup/VK-GL-CTS,KhronosGroup/VK-GL-CTS,KhronosGroup/Vulkan-CTS,KhronosGroup/VK-GL-CTS,googlestadia/VK-GL-CTS,KhronosGroup/Vulkan-CTS,KhronosGroup/Vulkan-CTS,KhronosGroup/Vulkan-CTS,KhronosGroup/VK-GL-CTS,googlestadia/VK-GL-CTS,googlestadia/VK-GL-CTS,KhronosGroup/VK-GL-CTS