Add device locale as first choice in locale picker

src/main/java/org/tasks/locale/Locale.java

@@ -64,6 +64,10 @@ public class Locale {
         hasUserOverrides = !(deviceLocale.equals(appLocale) && appDirectionality == deviceDirectionality) && atLeastJellybeanMR1();
     }
 
+    public java.util.Locale getDeviceLocale() {
+        return deviceLocale;
+    }
+
     public java.util.Locale getLocale() {
         return appLocale;
     }

src/main/java/org/tasks/locale/LocalePickerDialog.java

@@ -41,6 +41,7 @@ public class LocalePickerDialog extends InjectingDialogFragment {
     @Override
     public Dialog onCreateDialog(Bundle savedInstanceState) {
         final List<Locale> locales = new ArrayList<>();
+        locales.add(locale.withLanguage(null)); // device locale
         for (String override : getResources().getStringArray(R.array.localization)) {
             locales.add(locale.withLanguage(override));
         }
@@ -59,13 +60,6 @@ public class LocalePickerDialog extends InjectingDialogFragment {
                     }
                 })
                 .setNegativeButton(android.R.string.cancel, null)
-                .setNeutralButton(R.string.default_value, new DialogInterface.OnClickListener() {
-                    @Override
-                    public void onClick(DialogInterface dialogInterface, int i) {
-                        dialogInterface.dismiss();
-                        callback.onLocaleSelected(null);
-                    }
-                })
                 .show();
     }
 

src/main/java/org/tasks/preferences/BaseBasicPreferences.java

@@ -7,6 +7,7 @@ import android.content.Intent;
 import android.os.Bundle;
 import android.preference.Preference;
 
+import com.google.common.base.Strings;
 import com.jakewharton.processphoenix.ProcessPhoenix;
 import com.todoroo.astrid.activity.TaskListActivity;
 import com.todoroo.astrid.api.Filter;
@@ -188,10 +189,10 @@ public abstract class BaseBasicPreferences extends InjectingPreferenceActivity i
 
     @Override
     public void onLocaleSelected(Locale newValue) {
-        if (newValue == null) {
+        String override = newValue.getLanguageOverride();
+        if (Strings.isNullOrEmpty(override)) {
             preferences.remove(R.string.p_language);
         } else {
-            String override = newValue.getLanguageOverride();
             preferences.setString(R.string.p_language, override);
             tracker.reportEvent(Tracking.Events.SET_PREFERENCE, R.string.p_language, override);
         }