xwayland/glamor/gbm: use GBM_FORMAT_ARGB8888 for 24-bit on ES
On Mesa, when we request GBM_FORMAT_XRGB8888, driver set surface storage format to GL_RGB8, which breaks GL ES rendering (on any GL ES version). If we force set gbm_format to GBM_FORMAT_ARGB8888, then rendering will happen and working.
Fixes #1288 (closed)
Fixes #1356 (closed)
Fixes: mesa/mesa!5034 (merged)
It is an alternative to !934 (merged).
Edited by Konstantin