Add proactive hints container

This replaces all other chips containers and causes minimal
layout overhead: It is strictly within the task itself and
causes zero jank or space issues.

Screenshots:
https://drive.google.com/corp/drive/folders/1-3ZNCJtWc9_cgmP1nNd8U1yvpCr6GGoq
Test: manual
Change-Id: I5e22a34c4dc1ac3e73c4d5c913befc2360cb388e

quickstep/res/layout/task.xml

@@ -61,4 +61,14 @@
             android:gravity="center_vertical"
         />
     </com.android.quickstep.views.DigitalWellBeingToast>
+
+    <FrameLayout
+        android:id="@+id/proactive_suggest_container"
+        android:layout_width="match_parent"
+        android:layout_height="36dp"
+        android:gravity="center"
+        android:layout_gravity="bottom|center"
+        android:translationY="20dp"
+        android:elevation="4dp"
+     />
 </com.android.quickstep.views.TaskView>