SF: move idle timer to refresh rate configs

Move Idle timer management to RefreshRateConfigs to be able to maintain
separate timer for each display.

Bug: 188838426
Test: check idle timer is still working for both kernel idle timer and
      SF idle timer
Change-Id: If0bd6c9a1ba7e204160e722edc6aedaaeef84997
diff --git a/services/surfaceflinger/Scheduler/VSyncReactor.cpp b/services/surfaceflinger/Scheduler/VSyncReactor.cpp
index 7b5d462..ee973f7 100644
--- a/services/surfaceflinger/Scheduler/VSyncReactor.cpp
+++ b/services/surfaceflinger/Scheduler/VSyncReactor.cpp
@@ -42,6 +42,7 @@
       : mClock(std::move(clock)),
         mTracker(tracker),
         mPendingLimit(pendingFenceLimit),
+        // TODO(adyabr): change mSupportKernelIdleTimer when the active display changes
         mSupportKernelIdleTimer(supportKernelIdleTimer) {}
 
 VSyncReactor::~VSyncReactor() = default;