Bind the driver uniforms set only when actually updating them.

Bug: angleproject:4261
Change-Id: Ie1f1ab61eef58c5e0c713d285050c79c4cfccb32
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1986928
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Mohan Maiya <m.maiya@samsung.com>