Include also Dark Theme setting in backup file

app/src/main/kotlin/com/tutpro/baresip/Config.kt

@@ -2,6 +2,7 @@ package com.tutpro.baresip
 
 import android.Manifest
 import android.content.Context
+import androidx.appcompat.app.AppCompatDelegate
 import java.io.File
 import java.net.InetAddress
 import java.nio.charset.StandardCharsets
@@ -79,6 +80,14 @@ object Config {
             BaresipService.dynDns = true
         }
 
+        val darkTheme = previousVariable("dark_theme")
+        Preferences(ctx).displayTheme = if (darkTheme == "yes") {
+            config = "${config}dark_theme yes\n"
+            AppCompatDelegate.MODE_NIGHT_YES
+        } else {
+            AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM
+        }
+
         var contactsMode = previousVariable("contacts_mode").lowercase()
         if (contactsMode != "") {
             if (contactsMode != "baresip" &&

app/src/main/kotlin/com/tutpro/baresip/ConfigActivity.kt

@@ -580,8 +580,12 @@ class ConfigActivity : AppCompatActivity() {
                     AppCompatDelegate.MODE_NIGHT_YES
                 else
                     AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM
-                if (oldDisplayTheme != newDisplayTheme)
+                if (oldDisplayTheme != newDisplayTheme) {
                     Preferences(applicationContext).displayTheme = newDisplayTheme
+                    Config.replaceVariable("dark_theme",
+                        if (darkTheme.isChecked) "yes" else "no")
+                    save = true
+                }
 
                 if (oldContactsMode != contactsMode) {
                     Config.replaceVariable("contacts_mode", contactsMode)

app/src/main/kotlin/com/tutpro/baresip/MainActivity.kt

@@ -720,11 +720,6 @@ class MainActivity : AppCompatActivity() {
             }
         }
 
-        if (Preferences(applicationContext).displayTheme != AppCompatDelegate.getDefaultNightMode()) {
-            AppCompatDelegate.setDefaultNightMode(Preferences(applicationContext).displayTheme)
-            delegate.applyDayNight()
-        }
-
     } // OnCreate
 
     override fun onStart() {
@@ -1028,6 +1023,10 @@ class MainActivity : AppCompatActivity() {
                     aorSpinner.tag = BaresipService.uas[0].account.aor
                 }
             }
+            if (Preferences(applicationContext).displayTheme != AppCompatDelegate.getDefaultNightMode()) {
+                AppCompatDelegate.setDefaultNightMode(Preferences(applicationContext).displayTheme)
+                delegate.applyDayNight()
+            }
             handleNextEvent()
             return
         }