Fixes previous PR - FIX #2918 Add option for default language for file descriptions (#3020)

* FIX #2918 Add option for default language for file descriptions

* navigation menu error fixed and improvement of code quality

* error language description default fixed

* adapter language selected fixed

* local language selected per default in description language

* Use a better string and variable name as required in review 1

* Add comments

* Add previously missing setValue methods so that list item will be chosen along with the summary

* Add missing Javadocs

* Fix capitalization

* Lint and formatting issues

* Rename methods so it's clearer they are to do with languages

* Use default kv store instead of shared preferences variable

* Make sure saved language code from settings activity is handled on init

app/src/main/res/values/strings.xml

@@ -558,4 +558,5 @@ Upload your first media by tapping on the add button.</string>
   <string name="upload_cancelled">Cancelled Upload</string>
   <string name="previous_image_title_description_not_found">There is no data for previous image\'s title or description</string>
   <string name="dialog_box_text_nomination">Why should %1$s be deleted?</string>
+  <string name="default_description_language">Default description language</string>
 </resources>

app/src/main/res/xml/preferences.xml

@@ -29,6 +29,11 @@
             android:inputType="number"
             android:maxLength="3" />
 
+        <fr.free.nrw.commons.ui.LongTitlePreferences.LongTitleListPreference
+            android:key="descriptionDefaultLanguagePref"
+            android:title= "@string/default_description_language"
+            android:summary="English" />
+
         <fr.free.nrw.commons.ui.LongTitlePreferences.LongTitleSwitchPreference
             android:key="useAuthorName"
             android:title="@string/preference_author_name_toggle"