android: compatibility for Android 8 (#326)

apps/readest-app/src-tauri/gen/android/app/src/main/java/com/bilingify/readest/MainActivity.kt

@@ -1,5 +1,6 @@
 package com.bilingify.readest
 
+import android.os.Build
 import android.os.Bundle
 import android.view.View
 import android.view.WindowInsets
@@ -10,14 +11,23 @@ class MainActivity : TauriActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
         enableEdgeToEdge()
         super.onCreate(savedInstanceState)
-	
-	hideSystemUI()
+	      
+        hideSystemUI()
     }
 
     private fun hideSystemUI() {
-        window.decorView.windowInsetsController?.let { controller ->
-            controller.hide(WindowInsets.Type.systemBars())
-            controller.systemBarsBehavior = WindowInsetsController.BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+            window.decorView.windowInsetsController?.let { controller ->
+                controller.hide(WindowInsets.Type.systemBars())
+                controller.systemBarsBehavior = WindowInsetsController.BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE
+            }
+        } else {
+            @Suppress("DEPRECATION")
+            window.decorView.systemUiVisibility = (
+                View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY
+                        or View.SYSTEM_UI_FLAG_FULLSCREEN
+                        or View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
+            )
         }
     }
 }