Add tracing for b/134532571

Bug: 134172603
Bug: 134532571
Change-Id: I75c8e0212a9b35d33842d5380fbe733b486be932
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index 855535b..7e02168 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -879,6 +879,9 @@
 
     @Override
     protected void onStart() {
+        if (TestProtocol.sDebugTracing) {
+            Log.d(TestProtocol.NO_OVERVIEW_EVENT_TAG, "Launcher.onStart");
+        }
         RaceConditionTracker.onEvent(ON_START_EVT, ENTER);
         super.onStart();
         if (mLauncherCallbacks != null) {