Introduce TaskOrganizer

A first take at the TaskOrganizer API for allowing SysUI to control task presentation.
In this CL we introduce the first two primitives:
        1. The interface itself for implementation by SysUI
        2. Support for organizing a given windowing mode (but atm really only PIP)
We include a sample app that manages the PIP from an APPLICATION_OVERLAY window.

Bug: 139371701
Test: wmtests/TaskOrganizerTests. TaskOrganizerPipTest
Change-Id: I44a8ed311bc5f06285bba2c6ff3b37a7d19a9190
diff --git a/tests/TaskOrganizerTest/Android.bp b/tests/TaskOrganizerTest/Android.bp
new file mode 100644
index 0000000..8a13dbc
--- /dev/null
+++ b/tests/TaskOrganizerTest/Android.bp
@@ -0,0 +1,22 @@
+//
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+android_test {
+    name: "TaskOrganizerTest",
+    srcs: ["**/*.java"],
+    platform_apis: true,
+    certificate: "platform",
+}