This VK extension exposes features that are not necessary for
GL_OES_shader_image_atomic.  Instead, support for necessary features for
VK_FORMAT_R32_SFLOAT is used to determine support for this GL extension.

Bug: angleproject:5342
Change-Id: Ia504cba69ffe51cfd7da69df28f58563cb1f0744
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2536908
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Mohan Maiya <m.maiya@samsung.com>