Merge gamification branch with master (#1752)

* Quiz  (#1629)

*  Layout inflated

*  Layout for mcq added

*  Inflated Basic Layout

*  Implemented basic flow

*  Added the basic implementation pf score

*  Added the result layout

*  Added the result layout

*  Added functionality to set result

*  Changed the launcher intent to Quiz Activity for testing purpose

*  Explanations of answers added

*  Improved the layout of quiz result a bit

*  Fixed some minor issues

*  Fixed build issues

* Api Added and basic structure for calling implemented

* Added intents

*  Added the title

*  Fixed image error and improved quality of pr

*  Made separate class for checking quiz

*  Added counter

* Implemented back and next for quiz result

*  Added back functionality to quiz

*  Added progressBar

*  Fixed bugs

*  Improved code quality

*  Imporved code Quality

*  Updated strings

*  Added share screenshot function

*  Added checks and improved UI

*  Removed unused string

*  Removed unused string

* Adding checks and improving code quality

* Changed string

* Improved code quality

* Update strings.xml

* Update MediaWikiApi.java

* Fix build

app/src/main/java/fr/free/nrw/commons/achievements/AchievementsActivity.java

@@ -221,7 +221,7 @@ public class AchievementsActivity extends NavigationBaseActivity {
     private void setRevertCount(){
         if(checkAccount()) {
             compositeDisposable.add(mediaWikiApi
-                    .getRevertCount(sessionManager.getCurrentAccount().name)
+                    .getRevertRespObjectSingle(sessionManager.getCurrentAccount().name)
                     .subscribeOn(Schedulers.io())
                     .observeOn(AndroidSchedulers.mainThread())
                     .subscribe(