Help fallbacks and intent work

- Handle a backup URI, so that if the specified URI is not available,
   another can be used.
 - Add some data to help intents when they are intent URIs
 - Fill in the context with a classname when it isn't present

Bug: 15475009
Change-Id: I7050fa61121901929e650b20bd7a0ae21e8ba207

src/com/android/settings/fingerprint/FingerprintSettings.java

@@ -542,7 +542,7 @@ public class FingerprintSettings extends SubSettings {
         @Override
         public void onClick(View widget) {
             Context ctx = widget.getContext();
-            Intent intent = HelpUtils.getHelpIntent(ctx, getURL());
+            Intent intent = HelpUtils.getHelpIntent(ctx, getURL(), ctx.getClass().getName());
             try {
                 ctx.startActivity(intent);
             } catch (ActivityNotFoundException e) {