Document thrown IllegalArgumentException.

Change-Id: I502f91e3c1130c14ad8f67934bf52a7206de302f

Author: mathewinwood

core/java/android/content/pm/PackageManager.java

@@ -2527,6 +2527,7 @@ public abstract void setApplicationEnabledSetting(String packageName,
      * {@link #COMPONENT_ENABLED_STATE_DEFAULT}.  The last one means the
      * application's enabled state is based on the original information in
      * the manifest as found in {@link ComponentInfo}.
+     * @throws IllegalArgumentException if the named package does not exist.
      */
     public abstract int getApplicationEnabledSetting(String packageName);