WM: Move WindowManagerPolicy, DisplayFrames and WindowManagerInternal into services

Splits WindowManagerPolicy into a framework and a services part, preventing concepts that are
internal to the window manager from leaking out into the framework.

Test: make droid
Change-Id: I7b6a54f55f76f6fbb5f27090981b8f1d4d8be88b
diff --git a/services/core/java/com/android/server/wm/DragDropController.java b/services/core/java/com/android/server/wm/DragDropController.java
index 4567e10..65951dc 100644
--- a/services/core/java/com/android/server/wm/DragDropController.java
+++ b/services/core/java/com/android/server/wm/DragDropController.java
@@ -36,9 +36,10 @@
 import android.view.SurfaceControl;
 import android.view.SurfaceSession;
 import android.view.View;
-import android.view.WindowManagerInternal.IDragDropCallback;
+
 import com.android.internal.util.Preconditions;
 import com.android.server.input.InputWindowHandle;
+import com.android.server.wm.WindowManagerInternal.IDragDropCallback;
 
 /**
  * Managing drag and drop operations initiated by View#startDragAndDrop.