Add stencil8 option to Depth and Stencil of configs based on
support of stencil8 format from GLES.
Add stencil8 to configs
Adjust dEQP-EGL expectations
Unblocks dEQP-EGL.functional.*.*_no_depth_stencil tests
Test: angle_deqp_egl_tests

Bug: angleproject:3231
Change-Id: I57d7085a71a5b0dc45803351c9116a1694668852
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2430191Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>