Make UncivGame.isInitialized inaccessible outside of the class hierarchy (#9651)

* Make UncivGame.isInitialized inaccessible outside of the class hierarchy

* Fix JvmName

android/src/com/unciv/app/AndroidGame.kt

@@ -78,4 +78,5 @@ class AndroidGame(private val activity: Activity) : UncivGame() {
         }
     }
 
+    fun isInitializedProxy() = super.isInitialized
 }

android/src/com/unciv/app/AndroidLauncher.kt

@@ -70,7 +70,7 @@ open class AndroidLauncher : AndroidApplication() {
 
     override fun onPause() {
         val game = this.game!!
-        if (game.isInitialized
+        if (game.isInitializedProxy()
                 && game.gameInfo != null
                 && game.settings.multiplayer.turnCheckerEnabled
                 && game.files.getMultiplayerSaves().any()

core/src/com/unciv/UncivGame.kt

@@ -137,7 +137,9 @@ open class UncivGame(val isConsoleMode: Boolean = false) : Game(), PlatformSpeci
     var worldScreen: WorldScreen? = null
         private set
 
-    var isInitialized = false
+    /** Flag used only during initialization until the end of [create] */
+    protected var isInitialized = false
+        private set
 
     /** A wrapped render() method that crashes to [CrashScreen] on a unhandled exception or error. */
     private val wrappedCrashHandlingRender = { super.render() }.wrapCrashHandlingUnit()