Revert "[legacy sf flag] - Remove legacyFrontEndEnabled"

This reverts commit 11e197a2e438f0ea16066ff6118294a5fa3b26a3.

Reason for revert: caused regression in arc.PlayStore.betty_vm see http://b/337352234

Change-Id: I9ba883f0190b82ac1e00ed47ace8bec4e8a46fa6
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index c56567b..e7d2a11 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -3218,6 +3218,10 @@
     mFlinger->mTimeStats->setPostTime(layerId, mDrawingState.frameNumber, getName().c_str(),
                                       mOwnerUid, postTime, getGameMode());
 
+    if (mFlinger->mLegacyFrontEndEnabled) {
+        recordLayerHistoryBufferUpdate(getLayerProps(), systemTime());
+    }
+
     setFrameTimelineVsyncForBufferTransaction(info, postTime);
 
     if (dequeueTime && *dequeueTime != 0) {