Work on issue #16683269: system_server still leaking memory

Fix a small temporary leak of app crash dialogs, which weren't
removing their timeout message.

Change-Id: Iee90b5fa2be700e3006388f32145ce4b14baa2ec

services/core/java/com/android/server/am/AppErrorDialog.java

@@ -94,6 +94,9 @@ final class AppErrorDialog extends BaseErrorDialog {
             }
             mResult.set(msg.what);
 
+            // Make sure we don't have time timeout still hanging around.
+            removeMessages(FORCE_QUIT);
+
             // If this is a timeout we won't be automatically closed, so go
             // ahead and explicitly dismiss ourselves just in case.
             dismiss();