Fix issue #2093608: Calendar widget takes a few seconds to launch

Avert your eyes!

The key change here is that RemoteViews can now call a Context API to
start its pending intent, which inside of the activity manager we can
use to determine to cancel the timeout delay for external entities
to disrupt the home screen.

Change-Id: If097cf7478cbed7a3c04a304050bd7fd5703d197
diff --git a/core/java/android/content/Intent.java b/core/java/android/content/Intent.java
index fc977c8..1359761 100644
--- a/core/java/android/content/Intent.java
+++ b/core/java/android/content/Intent.java
@@ -2334,6 +2334,13 @@
      */
     public static final int FLAG_RECEIVER_BOOT_UPGRADE = 0x10000000;
 
+    /**
+     * @hide Flags that can't be changed with PendingIntent.
+     */
+    public static final int IMMUTABLE_FLAGS =
+            FLAG_GRANT_READ_URI_PERMISSION
+            | FLAG_GRANT_WRITE_URI_PERMISSION;
+    
     // ---------------------------------------------------------------------
     // ---------------------------------------------------------------------
     // toUri() and parseUri() options.