SF: Tidy naming of mode set FSM

Rename {Desired,Upcoming}ActiveMode to {Desired,Pending}Mode for clarity
that the FSM is in one of desired/pending/active states.

Rename clearDesiredActiveModeState to dropModeRequest, as its purpose is
to undo the effect of a DisplayModeRequest, regardless of FSM state.

Rename desiredActiveModeChangeDone to applyActiveMode, as it pertains to
applying the DisplayModeRequest that has become active to the Scheduler.
This function will later be moved from SF to Scheduler.

Bug: 255635711
Test: presubmit
Change-Id: Ie7fd9a353e38325d7b8dfd1d1143c7d52e5ad58e
diff --git a/services/surfaceflinger/Scheduler/RefreshRateSelector.h b/services/surfaceflinger/Scheduler/RefreshRateSelector.h
index 545b939..40e9a83 100644
--- a/services/surfaceflinger/Scheduler/RefreshRateSelector.h
+++ b/services/surfaceflinger/Scheduler/RefreshRateSelector.h
@@ -16,9 +16,6 @@
 
 #pragma once
 
-#include <algorithm>
-#include <numeric>
-#include <set>
 #include <type_traits>
 #include <utility>
 #include <variant>
@@ -258,9 +255,8 @@
                 mMaxRefreshRateModeIt->second->getPeakFps()};
     }
 
-    ftl::Optional<FrameRateMode> onKernelTimerChanged(
-            std::optional<DisplayModeId> desiredActiveModeId, bool timerExpired) const
-            EXCLUDES(mLock);
+    ftl::Optional<FrameRateMode> onKernelTimerChanged(ftl::Optional<DisplayModeId> desiredModeIdOpt,
+                                                      bool timerExpired) const EXCLUDES(mLock);
 
     void setActiveMode(DisplayModeId, Fps renderFrameRate) EXCLUDES(mLock);