Dump RefreshRateConfigs

Add RefreshRateConfigs dump to SurfaceFligner dumpsys, dumping the
current display mode and the list of supported display modes.
This is very useful for debugging because SF works with two types of
IDs  (HwcConfigIndexType and hal::HWConfigId).

Bug: 161776961
Test: adb shell dumpsys SurfaceFlinger
Change-Id: I628b842d46308a140b2985398672b4dce2e4b952