Tests are still loading ANGLE's opengl32.dll instead of system's
This is because external drivers are trying to load opengl32.dll
Workaround: renamed to libGL.dll, need to change back when copying
dll over for loading

Bug: angleproject:3641
Change-Id: I051adc1fbb488a704c99718ad4a2f74bb7756cbd
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1697290
Commit-Queue: Clemen Deng <clemendeng@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>