Refactor help menu stuff into a controller

This is a clean up to action bar menu item pattern, we will use the same
pattern to build search icon on all pages in a later change.

Bug: 68814716
Test: robotests
Change-Id: Iedd3ec263e8ccb63ed75ec7a95b28c00878b1de4
diff --git a/src/com/android/settings/DisplaySettings.java b/src/com/android/settings/DisplaySettings.java
index d67758a..b91481a 100644
--- a/src/com/android/settings/DisplaySettings.java
+++ b/src/com/android/settings/DisplaySettings.java
@@ -77,7 +77,7 @@
     }
 
     @Override
-    protected int getHelpResource() {
+    public int getHelpResource() {
         return R.string.help_uri_display;
     }