Update transform feedback tests

Update transform feedback tests

GLES3.2 spec made a change in 2018/5/14 version, that The
TRANSFORM_FEEDBACK_BUFFER_BINDING generic buffer binding point has now
been moved to context state, rather than per-object state, and should
be unaffected by glBindTransformFeedback command.

Some tests follow the old standard that they use glBindTransformFeedback
function to change the binding point status.

Components: OpenGL

Affects: KHR-GLES31.core.vertex_attrib_binding.advanced-iterations

VK-GL-CTS issue: 1275

Change-Id: I9a0296ef273321ef8b039986b92baf2353838a99