Use WrapSharedImages() for media unittests

As part of the ClientSharedImage refactoring, this CL uses
WrapSharedImages() to replace the WrapNativeTextures() calls in
media unittests.

Bug: 1494911
Change-Id: Iec35d151508d17dce8bd16f9a0406ea63861f09d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5399396


Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: Mingjing Zhang <mjzhang@chromium.org>
Reviewed-by: Vasiliy Telezhnikov <vasilyt@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1279872}