Create the test Texture2DTestES3::ChangeTexSizeWithTexStorage() which
confirms that releaseImage() needs to be called by
setStorageMultisample() to re-allocate the Image after ensuring the
ImageHelpers has been created correctly.

Bug: angleproject:5254
Bug: angleproject:5256
Test: Texture2DTestES3::ChangeTexSizeWithTexStorage
Change-Id: I7ede9f7360b73bc445125b2a99efd60c9c4c110d
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2472999
Commit-Queue: Tim Van Patten <timvp@google.com>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>