Transform feedback buffer state is managed by TransformFeedbackGL, the
state tracked in StateManagerGL is not correct.

BUG=angleproject:3900

Change-Id: I73f7b9b1c8d3b4087e25eb4cf3844faf210793a0
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1848392Reviewed-by: Jonah Ryan-Davis <jonahr@google.com>
Commit-Queue: Geoff Lang <geofflang@chromium.org>