Fix bugs 226264 and 2265943 - Home stopped responding to touch, but all-apps & notification panel

still work

I knew it was a problem with mWaitingForResult, which I'm still not convinced we need, but
Jeff Sharkey was able to find repro steps, so he's my new hero.  The steps were:
  1. Open add menu (long pressing or menu > add)
  2. Turn off the screen
  3. Turn back on & unlock
  4. Poof.
The problem was that when we get ACTION_CLOSE_SYSTEM_DIALOGS intents, we're dismissing the dialogs,
not canceling them.  I think we actually want to cancel them, but there's no easy way to do that
with the Activity class, so just clear mWaitingForResult by hand in closeSystemDialogs().

src/com/android/launcher2/Launcher.java

@@ -831,6 +831,9 @@ public final class Launcher extends Activity
         } catch (Exception e) {
             // An exception is thrown if the dialog is not visible, which is fine
         }
+
+        // Whatever we were doing is hereby canceled.
+        mWaitingForResult = false;
     }
 
     @Override
@@ -839,11 +842,9 @@ public final class Launcher extends Activity
 
         // Close the menu
         if (Intent.ACTION_MAIN.equals(intent.getAction())) {
+            // also will cancel mWaitingForResult.
             closeSystemDialogs();
 
-            // Whatever we were doing is hereby canceled.
-            mWaitingForResult = false;
-
             // Set this flag so that onResume knows to close the search dialog if it's open,
             // because this was a new intent (thus a press of 'home' or some such) rather than
             // for example onResume being called when the user pressed the 'back' button.