Allow for multiple locale and stabilise set language call

src/BasePlatform.ts

@@ -258,7 +258,7 @@ export default abstract class BasePlatform {
         return null;
     }
 
-    async setLanguage(language: string) {
+    async setLanguage(preferredLangs: string[]) {
         throw new Error("Unimplemented");
     }
 

src/components/views/settings/tabs/user/GeneralUserSettingsTab.js

@@ -194,8 +194,8 @@ export default class GeneralUserSettingsTab extends React.Component {
         this.setState({language: newLanguage});
         const platform = PlatformPeg.get();
         if (platform) {
-            platform.reload();
             platform.setLanguage(newLanguage);
+            platform.reload();
         }
     };