Code cleanups (#3264)

* Kotlin 1.8.10

https://github.com/JetBrains/kotlin/releases/tag/v1.8.10

* Migrate onActivityCreated to onViewCreated

* More final modifiers

* Java Cleanups

* Kotlin cleanups

* More final modifiers

* Const value TOOLBAR_HIDE_DELAY_MS

* Revert

app/src/main/java/com/keylesspalace/tusky/util/LocaleExtensions.kt

@@ -30,7 +30,7 @@ val Locale.modernLanguageCode: String
 fun Locale.getTuskyDisplayName(context: Context): String {
     return context.getString(
         R.string.language_display_name_format,
-        this?.displayLanguage,
-        this?.getDisplayLanguage(this)
+        displayLanguage,
+        getDisplayLanguage(this)
     )
 }