rationalize launcher backup logging

enough data to debug dogfood issues
easy switch to move to quieter production mode
common switch across all three classes

Bug: 12545310
Change-Id: Icb4ad7174f20884c6993140149db590d66f6e006
diff --git a/src/com/android/launcher3/LauncherPreferencesBackupHelper.java b/src/com/android/launcher3/LauncherPreferencesBackupHelper.java
index 1ac6ff9..6f9c05c 100644
--- a/src/com/android/launcher3/LauncherPreferencesBackupHelper.java
+++ b/src/com/android/launcher3/LauncherPreferencesBackupHelper.java
@@ -19,9 +19,13 @@
 import android.app.backup.BackupDataInputStream;
 import android.app.backup.SharedPreferencesBackupHelper;
 import android.content.Context;
+import android.util.Log;
 
 public class LauncherPreferencesBackupHelper extends SharedPreferencesBackupHelper {
 
+    private static final String TAG = "LauncherPreferencesBackupHelper";
+    private static final boolean VERBOSE = LauncherBackupAgentHelper.VERBOSE;
+
     private final boolean mRestoreEnabled;
 
     public LauncherPreferencesBackupHelper(Context context,  String sharedPreferencesKey,
@@ -33,6 +37,7 @@
     @Override
     public void restoreEntity(BackupDataInputStream data) {
         if (mRestoreEnabled) {
+            if (VERBOSE) Log.v(TAG, "restoring preferences");
             super.restoreEntity(data);
         }
     }