SF: update consistent criteria for heuristic refresh rate calculation

Enlarge the consistent criteria to apply heuristic logic for more cases.
To prevent introducing oscillation, this makes sure to only select a
valid know refresh rate if all the frametime in the layer history have
the same nearest known refresh rate.

Bug: 299201319
Test: presubmit
Change-Id: Ie317f7fe337c84c2c7314069cba1bd02a147bf6b
diff --git a/services/surfaceflinger/common/FlagManager.cpp b/services/surfaceflinger/common/FlagManager.cpp
index e2a1498..35dd428 100644
--- a/services/surfaceflinger/common/FlagManager.cpp
+++ b/services/surfaceflinger/common/FlagManager.cpp
@@ -121,6 +121,7 @@
     DUMP_READ_ONLY_FLAG(hdcp_level_hal);
     DUMP_READ_ONLY_FLAG(multithreaded_present);
     DUMP_READ_ONLY_FLAG(add_sf_skipped_frames_to_trace);
+    DUMP_READ_ONLY_FLAG(use_known_refresh_rate_for_fps_consistency);
 
 #undef DUMP_READ_ONLY_FLAG
 #undef DUMP_SERVER_FLAG
@@ -190,6 +191,7 @@
 FLAG_MANAGER_READ_ONLY_FLAG(hdcp_level_hal, "")
 FLAG_MANAGER_READ_ONLY_FLAG(multithreaded_present, "debug.sf.multithreaded_present")
 FLAG_MANAGER_READ_ONLY_FLAG(add_sf_skipped_frames_to_trace, "")
+FLAG_MANAGER_READ_ONLY_FLAG(use_known_refresh_rate_for_fps_consistency, "")
 
 /// Trunk stable server flags ///
 FLAG_MANAGER_SERVER_FLAG(late_boot_misc2, "")