Add return animation functionality to TransitionAnimator.

Bug: 323863002
Flag: ACONFIG com.android.systemui.shared.return_animation_framework_library DISABLED
Test: Manually tested existing use cases with the flag on and off (same
behavior), added unit test

Change-Id: I391c6ae784871e17262649d0f17343ac87b6a6d4
diff --git a/packages/SystemUI/tests/AndroidManifest.xml b/packages/SystemUI/tests/AndroidManifest.xml
index 572a6c1..0dbbe63 100644
--- a/packages/SystemUI/tests/AndroidManifest.xml
+++ b/packages/SystemUI/tests/AndroidManifest.xml
@@ -224,6 +224,5 @@
 
     <instrumentation android:name="android.testing.TestableInstrumentation"
         android:targetPackage="com.android.systemui.tests"
-        android:label="Tests for SystemUI">
-    </instrumentation>
+        android:label="Tests for SystemUI" />
 </manifest>