Modify AppHeaderController to provide UI for notif settings

- The AppHeaderController is no longer a singleton. Each time appheader
  should be updated we will create a new controller. It acts as a
  builder/mutator, user provides customizable inputs, and the controller
  will bind everything to UI when calling done().

Bug: 32442716
Test: RunSettingsRoboTests
Change-Id: Icfc5bcd8bc170a02b57432d864eaddf71db0d5b4

src/com/android/settings/applications/ApplicationFeatureProvider.java

@@ -16,8 +16,14 @@
 
 package com.android.settings.applications;
 
+import android.app.Fragment;
+import android.view.View;
+
 public interface ApplicationFeatureProvider {
 
-    AppHeaderController getAppHeaderController();
+    /**
+     * Returns a new {@link AppHeaderController} instance to customize app header.
+     */
+    AppHeaderController newAppHeaderController(Fragment fragment, View appHeader);
 }