Also enable the FramebufferObjectTest/* tests

Bug: angleproject:6058
Change-Id: Ia82c935e614ccc4ad2c69ccc08544ce2d302fbca
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2957954Reviewed-by: Cody Northrop <cnorthrop@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>