Follow the WebGL specification and ignore the values of UNPACK_FLIP_Y,
UNPACK_PREMULTIPLY_ALPHA, and UNPACK_COLORSPACE_CONVERSION
if the TexImageSource is an ImageBitmap.
https://registry.khronos.org/webgl/specs/latest/1.0/#6.10
Testing: There are no dedicated test results changes without the PR
#37634
which unblocks new testing scenarios with premultiplied ImageBitmap from
Blob/Canvas/Image sources.
Signed-off-by: Andrei Volykhin <andrei.volykhin@gmail.com>