Since these are per context, we can increase it (and subject to the
driver maxUniformBufferRange limit) to reduce the amount of descriptor
set allocated.

Bug: b/161391337
Change-Id: I89e5cf16ee377735c412e9a9a22c651e1c677ded
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2310910
Commit-Queue: Charlie Lao <cclao@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com>