Use glReadnPixels only if KHR_robustness is supported
glReadnPixels is introduced in KHR_robustness/GLES 3.2.
Use of this function in GLES 3.1 tests will result in segfault
on implementations that don't support KHR_robustness.
Components: AOSP, Framework
Affects: dEQP-GLES31.functional.debug.negative_coverage.callbacks.buffer.read_pixels_format_mismatch
VK-GL-CTS issue: 166
Google bug:
36122027
Change-Id: Idbe8734f7d82882ea99c75a8b74d693ac6dd831f
(cherry picked from commit
219019495770c221e92f43df3e76a954c613210d)