Bug 1262105 - Add link to SUMO article to content notifications preference. r=grisha

MozReview-Commit-ID: 3xDGpUnJw3I

--HG--
extra : rebase_source : 874cb2852df7efbfa33b83255c1aaea079f01ff9
extra : amend_source : f2e4c8454bf87ec7cca912c6fefb3ca2ff24f906

mobile/android/base/java/org/mozilla/gecko/preferences/GeckoPreferences.java

@@ -156,6 +156,7 @@ OnSharedPreferenceChangeListener
     private static final String PREFS_FAQ_LINK = NON_PREF_PREFIX + "faq.link";
     private static final String PREFS_FEEDBACK_LINK = NON_PREF_PREFIX + "feedback.link";
     public static final String PREFS_NOTIFICATIONS_CONTENT = NON_PREF_PREFIX + "notifications.content";
+    public static final String PREFS_NOTIFICATIONS_CONTENT_LEARN_MORE = NON_PREF_PREFIX + "notifications.content.learn_more";
     public static final String PREFS_NOTIFICATIONS_WHATS_NEW = NON_PREF_PREFIX + "notifications.whats_new";
 
     private static final String ACTION_STUMBLER_UPLOAD_PREF = AppConstants.ANDROID_PACKAGE_NAME + ".STUMBLER_PREF";
@@ -881,7 +882,8 @@ OnSharedPreferenceChangeListener
                         i--;
                         continue;
                     }
-                } else if (PREFS_NOTIFICATIONS_CONTENT.equals(key)) {
+                } else if (PREFS_NOTIFICATIONS_CONTENT.equals(key) ||
+                        PREFS_NOTIFICATIONS_CONTENT_LEARN_MORE.equals(key)) {
                     if (!FeedService.isInExperiment(this)) {
                         preferences.removePreference(pref);
                         i--;

mobile/android/base/resources/xml/preferences_notifications.xml

@@ -4,6 +4,11 @@
         android:title="@string/pref_content_notifications"
         android:summary="@string/pref_content_notifications_summary"
         android:defaultValue="true" />
+    <org.mozilla.gecko.preferences.AlignRightLinkPreference
+        android:key="android.not_a_preference.notifications.content.learn_more"
+        android:title="@string/pref_learn_more"
+        android:persistent="false"
+        url="https://support.mozilla.org/kb/notifications-firefox-android?utm_source=inproduct&amp;utm_medium=notifications&amp;utm_campaign=mobileandroid" />
     <SwitchPreference android:key="android.not_a_preference.notifications.whats_new"
         android:title="@string/pref_whats_new_notification"
         android:summary="@string/pref_whats_new_notification_summary"