Revert "Revert "Update Readback VTS to align with RenderEngine i..."

Revert "Revert "Update WaylandRenderSurface to accomodate interf..."

Revert "Revert "Add ExternalTexture class into RenderEngine inte..."

Revert submission 14199598-revert-14086921-renderengine-external-tex-QJNBWQMQEU

Reason for revert: Prepare for relanding
Reverted Changes:
I01e65a7f4:Revert "Update WaylandRenderSurface to accomodate ...
I7d58118c1:Revert "Update Readback VTS to align with RenderEn...
I1501890f4:Revert "Add ExternalTexture class into RenderEngin...

Change-Id: Ic2ee9311d22658ac77c8a94f6070324cf07b601b