UploadMediaDetailAdapter: made selecting a language deselect all others (#5883)

>> Made it so that selecting a language results in the hashmap storing the currently selected language(s) being cleared. Considered refactoring the hashmap storing this into a single pair storing the language positition index and its code, as only one language should ever be selected, however I am not confident that this would not introduce unintended side-effects

Author: cambo14

app/src/main/java/fr/free/nrw/commons/upload/UploadMediaDetailAdapter.java

@@ -407,7 +407,7 @@ public void onItemClick(AdapterView<?> adapterView, View view, int i,
                             recentLanguagesDao
                                 .addRecentLanguage(new Language(languageName, languageCode));
 
-                            selectedLanguages.remove(position);
+                            selectedLanguages.clear();
                             selectedLanguages.put(position, languageCode);
                             ((LanguagesAdapter) adapterView
                                 .getAdapter()).setSelectedLangCode(languageCode);
@@ -497,7 +497,7 @@ private void onRecentLanguageClicked(final Dialog dialog, final AdapterView<?> a
             }
             recentLanguagesDao.addRecentLanguage(new Language(languageName, languageCode));
 
-            selectedLanguages.remove(position);
+            selectedLanguages.clear();
             selectedLanguages.put(position, languageCode);
             ((RecentLanguagesAdapter) adapterView
                 .getAdapter()).setSelectedLangCode(languageCode);