Add API to disable snapshotting of activities

Test: runtest frameworks-services -c
com.android.server.wm.TaskSnapshotControllerTest
Test: Launch DisableScreenshotsActivity, go to recents, make sure
content is white.
Bug: 31339431

Change-Id: I329925d2fca389e561da3389a67fe888b5bb1033
diff --git a/services/tests/servicestests/src/com/android/server/wm/WindowTestsBase.java b/services/tests/servicestests/src/com/android/server/wm/WindowTestsBase.java
index 65efd9c..96481dd 100644
--- a/services/tests/servicestests/src/com/android/server/wm/WindowTestsBase.java
+++ b/services/tests/servicestests/src/com/android/server/wm/WindowTestsBase.java
@@ -42,6 +42,7 @@
 import static android.content.pm.ActivityInfo.RESIZE_MODE_UNRESIZEABLE;
 import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED;
 import static android.content.res.Configuration.EMPTY;
+import static android.content.res.Configuration.ORIENTATION_UNDEFINED;
 import static android.view.DisplayAdjustments.DEFAULT_DISPLAY_ADJUSTMENTS;
 import static android.view.WindowManager.LayoutParams.FIRST_APPLICATION_WINDOW;
 import static android.view.WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE;