Android6.0 Fix launcher3 crash when search.

Android6.0 使用lanucher3的搜索时出现crash，解决方法如下：

diff --git a/packages/apps/Launcher3/src/com/android/launcher3/Launcher.java b/packages/apps/Launcher3/src/com/android/launcher3/Launcher.java
index e550902..aba6363 100755
--- a/packages/apps/Launcher3/src/com/android/launcher3/Launcher.java
+++ b/packages/apps/Launcher3/src/com/android/launcher3/Launcher.java
@@ -2872,6 +2872,8 @@ public class Launcher extends Activity
     }
 
     private boolean startActivity(View v, Intent intent, Object tag) {
+           if(intent == null)
+                       return false;
         intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
         try {
             // Only launch using the new animation if the shortcut has not opted out (this is a