Use Search.SOURCE from android-common

The SOURCE (search source identifier) constant is moving
from hidden in android.app.SearchManager to com.android.common.Search.

Part of http://b/issue?id=2429556

Change-Id: I68fa792f2d452aadcb9216f5c780bd082ca5039f
diff --git a/src/com/android/launcher2/Launcher.java b/src/com/android/launcher2/Launcher.java
index 99b1b6c..646203c 100644
--- a/src/com/android/launcher2/Launcher.java
+++ b/src/com/android/launcher2/Launcher.java
@@ -16,6 +16,8 @@
 
 package com.android.launcher2;
 
+import com.android.common.Search;
+
 import android.app.Activity;
 import android.app.AlertDialog;
 import android.app.Dialog;
@@ -963,7 +965,7 @@
         }
         if (appSearchData == null) {
             appSearchData = new Bundle();
-            appSearchData.putString(SearchManager.SOURCE, "launcher-search");
+            appSearchData.putString(Search.SOURCE, "launcher-search");
         }
 
         final SearchManager searchManager =