More API changes.

Start moving Assist* stuff to android.app.assist.

Clean up some more of the VoiceInteractionSession APIs.

Clearly document that finish() is not the same as hide(),
always call hide() instead, and fix the finish() path to
also always do a hide to make sure everything is cleaned
up correctly.

Change-Id: I962d4069fcb34fe89547a95d395ae1b9fa3b4148
diff --git a/core/java/android/app/ActivityManagerNative.java b/core/java/android/app/ActivityManagerNative.java
index e4def1e..b6cec60 100644
--- a/core/java/android/app/ActivityManagerNative.java
+++ b/core/java/android/app/ActivityManagerNative.java
@@ -17,6 +17,8 @@
 package android.app;
 
 import android.app.ActivityManager.StackInfo;
+import android.app.assist.AssistContent;
+import android.app.assist.AssistStructure;
 import android.content.ComponentName;
 import android.content.IIntentReceiver;
 import android.content.IIntentSender;