Tightening up rotation behavior for PIP (1/3)

- Defer getting the default bounds until after the task has been reparented
  to the pinned stack
- Also move pinned stack-related methods into pinned stack window
  controller and listener

Bug: 36879891
Test: android.server.cts.ActivityManagerPinnedStackTests

Change-Id: Ib2bd81ad9e2a3829b556177010f39c7512ba35bf
diff --git a/services/core/java/com/android/server/am/PinnedActivityStack.java b/services/core/java/com/android/server/am/PinnedActivityStack.java
index 394e902..924e4af 100644
--- a/services/core/java/com/android/server/am/PinnedActivityStack.java
+++ b/services/core/java/com/android/server/am/PinnedActivityStack.java
@@ -21,6 +21,7 @@
 
 import com.android.server.am.ActivityStackSupervisor.ActivityContainer;
 import com.android.server.wm.PinnedStackWindowController;
+import com.android.server.wm.PinnedStackWindowListener;
 import com.android.server.wm.StackWindowController;
 
 import java.util.ArrayList;
@@ -29,7 +30,8 @@
 /**
  * State and management of the pinned stack of activities.
  */
-class PinnedActivityStack extends ActivityStack<PinnedStackWindowController> {
+class PinnedActivityStack extends ActivityStack<PinnedStackWindowController>
+        implements PinnedStackWindowListener {
 
     PinnedActivityStack(ActivityContainer activityContainer,
             RecentTasks recentTasks, boolean onTop) {