Refactor UserEventLogging, Add predictedRank, replace Bundle with Proto

b/26494415
- Removed bundle object that became redundant now that we have LauncherEvent proto
- Combined Stats and UserEventLogger as they are effectively doing same thing
- Removed parent field inside Target
- added predictedRank target inside Target

b/27967359
- make com.android.launcher3.action.LAUNCH broadcast explicit
Later CL: finish packageName/intent/componentHash/predictedRank fields

Change-Id: I441fb46c834f73e58a4d2324e8da7971e8713ec8
diff --git a/src/com/android/launcher3/LauncherCallbacks.java b/src/com/android/launcher3/LauncherCallbacks.java
index 635d413..f33cf83 100644
--- a/src/com/android/launcher3/LauncherCallbacks.java
+++ b/src/com/android/launcher3/LauncherCallbacks.java
@@ -1,12 +1,11 @@
 package com.android.launcher3;
 
-import android.content.ComponentName;
 import android.content.Intent;
 import android.graphics.Rect;
 import android.os.Bundle;
 import android.view.Menu;
 import android.view.View;
-import android.view.ViewGroup;
+
 import com.android.launcher3.allapps.AllAppsSearchBarController;
 import com.android.launcher3.logging.UserEventLogger;
 import com.android.launcher3.util.ComponentKey;