Revert "Revert "Revert "SF: Remove refresh_rate_switching flag."""

This reverts commit aa52b007.

Reason for revert: The original revert cause a failure: b/148821456. So the revert was created. Which caused a build failure b/148835312. Reverting the original change and fixing the test (that caused build failure) with it.

Bug: 148835312
Bug: 148821456
Bug: 148835894
Test: build, install on coral.
Test: adb shell /data/nativetest64/libsurfaceflinger_unittest/libsurfaceflinger_unittest
Change-Id: I48964c7c27ef53e8fb03d959ef85ee2ec64e1ed1