Merge "SurfaceFlinger: refresh rate calculation when no timestamps" into rvc-dev am: e7d62aa5 am: c1890298

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/native/+/11417684

Change-Id: I7fb625d571f1db7c097e32d7f9ffe43787b6ceac