Re-enable some previously expired histograms in overlay processing

These histograms are all related to CrOS multiple overlays
and are re-enabled for refactoring purposes.

Compositing.Display.OverlayProcessorOzone.MaxPlanesSupported
Compositing.Display.OverlayProcessorUsingStrategy.ShouldAttemptMultipleOverlays

Also add a new metric to measure the time we spent on DRM thread performing PageFlip operation:

Compositing.Display.DrmThreadProxy.CheckOverlayCapabilitiesSyncOnDrmThreadUs

Change-Id: Ib85d9ee1e5ce5e0f03f82fafb0ea86b57f06fc48
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6163879
Reviewed-by: Jonathan Ross <jonross@chromium.org>
Reviewed-by: Kramer Ge <fangzhoug@chromium.org>
Reviewed-by: Peter McNeeley <petermcneeley@google.com>
Commit-Queue: Hart Huang <harthuang@google.com>
Cr-Commit-Position: refs/heads/main@{#1405602}