Closes mozilla-mobile#1645. Remove feature flag for "Add search engine"

Author: liuche

app/src/main/java/org/mozilla/focus/settings/SettingsFragment.java

@@ -30,7 +30,6 @@
 import org.mozilla.focus.search.RadioSearchEngineListPreference;
 import org.mozilla.focus.search.SearchEngineManager;
 import org.mozilla.focus.telemetry.TelemetryWrapper;
-import org.mozilla.focus.utils.AppConstants;
 import org.mozilla.focus.widget.DefaultBrowserPreference;
 
 import java.util.Locale;
@@ -49,9 +48,7 @@ public interface ActionBarUpdater {
 
     public enum SettingsScreen {
         MAIN(R.xml.settings, R.string.menu_settings),
-        SEARCH_ENGINES(AppConstants.FLAG_MANUAL_SEARCH_ENGINE ?
-                R.xml.search_engine_settings_featureflag_manual :
-                R.xml.search_engine_settings,
+        SEARCH_ENGINES(R.xml.search_engine_settings,
                 R.string.preference_search_installed_search_engines),
         ADD_SEARCH(R.xml.manual_add_search_engine, R.string.tutorial_search_title),
         REMOVE_ENGINES(R.xml.remove_search_engines, R.string.preference_search_remove_title);
@@ -94,8 +91,7 @@ public void onCreate(@Nullable Bundle savedInstanceState) {
         settingsScreen = SettingsScreen.valueOf(getArguments().getString(SETTINGS_SCREEN_NAME, SettingsScreen.MAIN.name()));
         addPreferencesFromResource(settingsScreen.prefsResId);
 
-        setHasOptionsMenu((settingsScreen == SettingsScreen.SEARCH_ENGINES
-                && AppConstants.FLAG_MANUAL_SEARCH_ENGINE)
+        setHasOptionsMenu(settingsScreen == SettingsScreen.SEARCH_ENGINES
                 || settingsScreen == SettingsScreen.REMOVE_ENGINES);
     }
 
@@ -209,7 +205,7 @@ public void onResume() {
      * Refresh search engines list. Only runs if showing the "Installed search engines" screen.
      */
     private void refetchSearchEngines() {
-        if (settingsScreen == SettingsScreen.SEARCH_ENGINES && AppConstants.FLAG_MANUAL_SEARCH_ENGINE) {
+        if (settingsScreen == SettingsScreen.SEARCH_ENGINES) {
             final Preference pref = getPreferenceScreen()
                     .findPreference(getResources().getString(
                             R.string.pref_key_radio_search_engine_list));

app/src/main/java/org/mozilla/focus/utils/AppConstants.java

@@ -35,6 +35,4 @@ public static boolean isBetaBuild() {
     public static boolean supportsDownloadingFiles() {
         return true;
     }
-
-    public static final boolean FLAG_MANUAL_SEARCH_ENGINE = isDevBuild();
 }

app/src/main/res/xml/search_engine_settings.xml

@@ -3,7 +3,12 @@
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
-<!-- Changes should be mirrored to search_engine_settings_featureflag_manual, which is behind a feature flag. -->
+<!-- This preffed off by feature flag FLAG_MANUAL_SEARCH_ENGINE and corresponds to
+search_engine_settings.xml -->
 <PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
-    <org.mozilla.focus.search.SearchEngineChooserPreference />
+    <org.mozilla.focus.search.RadioSearchEngineListPreference
+        android:key="@string/pref_key_radio_search_engine_list"/>
+    <Preference
+        android:title="@string/preference_search_add2"
+        android:key="@string/pref_key_manual_add_search_engine"/>
 </PreferenceScreen>