Various fixes and improvements to window, activity.

- New meta-data you can add to a dock activity to have it launched by the
  home key when the device is in that dock.

- Fix a deadlock involving ActivityThread's internal content provider lock.

- New window flag to have a non-secure keyguard entirely dismissed when a
  window is displayed.

- New WindowManagerPolicy APIs to allow the policy to tell the system when
  a change it makes during layout may cause the wall paper or
  overall configuration to change.

- Fix a bug where an application token removed while one of its windows is
  animating could cause the animating window to get stuck on screen.

Change-Id: I6d33fd39edd796bb9bdfd9dd7e077b84ca62ea08

services/java/com/android/server/DockObserver.java

@@ -74,7 +74,8 @@ class DockObserver extends UEventObserver {
             if (category != null) {
                 intent = new Intent(Intent.ACTION_MAIN);
                 intent.addCategory(category);
-                intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+                intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK
+                        | Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
                 try {
                     mContext.startActivity(intent);
                 } catch (ActivityNotFoundException e) {