Previously glColorPointer would reject GL_UNSIGNED_BYTE.

This should be allowed in both the gles 1 and 1.1 specifications.
See page 6 of the gles 1 specification and page 20 of the gles 1.1
specification.

This change allows doodle jump to work on angle on both the gl
and vulkan backend

Bug: angleproject:4308
Tests: angle_end2end_tests
       --gtest_filter=VertexPointerTest.AssignRetrieveColorUnsignedByte*
Change-Id: I35f41b28d94cb34bc36256420b57793691b78cff
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2424465
Commit-Queue: Mohan Maiya <m.maiya@samsung.com>
Reviewed-by: Cody Northrop <cnorthrop@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>