Add APIs to remove tasks.

You can remove sub-tasks inside of a task, or an entire task.

When removing an entire task, you can have its process killed
as well.

When the process is killed, any running services will get an
onTaskRemoved() callback for them to do cleanup before their
process is killed (and the service possibly restarted).

Or they can set a new android:stopWithTask attribute to just
have the service automatically (cleanly) stopped at this point.

Change-Id: I1891bc2da006fa53b99c52f9040f1145650e6808
diff --git a/tests/ActivityTests/AndroidManifest.xml b/tests/ActivityTests/AndroidManifest.xml
index 6fa27ed..de3b6d1 100644
--- a/tests/ActivityTests/AndroidManifest.xml
+++ b/tests/ActivityTests/AndroidManifest.xml
@@ -17,6 +17,8 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.google.android.test.activity">
     <uses-permission android:name="android.permission.GET_TASKS" />
+    <uses-permission android:name="android.permission.REORDER_TASKS" />
+    <uses-permission android:name="android.permission.REMOVE_TASKS" />
     <uses-permission android:name="android.permission.READ_FRAME_BUFFER" />
     <application android:label="ActivityTest">
         <activity android:name="ActivityTestMain">