SF: Update RefreshRateOverlay before SF applies transactions

The current implementation of RefreshRateOverlay changes it's buffer
to reflect the upcoming refresh rate after SF applies transaction.
This is causing SF to see a layer update and reset the idle timer,
entering a live loop of refresh rate switches.

Instead, we update the RefreshRateOverlay when the refresh rate change is
done and before SF applies transactions for the next frame.

Bug: 192204776
Test: Enable RefreshRateOverlay on a device with idle timer enabled
Change-Id: Ie904d6f37b7a02126d52a6267246afaf33982eff