Android: Update exported app and editor theme

platform/android/java/app/res/values/themes.xml

@@ -1,7 +1,9 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
 
-	<style name="GodotAppMainTheme" parent="@android:style/Theme.Black.NoTitleBar"/>
+	<style name="GodotAppMainTheme" parent="@android:style/Theme.DeviceDefault.NoActionBar">
+		<item name ="android:windowDrawsSystemBarBackgrounds">false</item>
+	</style>
 
 	<style name="GodotAppSplashTheme" parent="Theme.SplashScreen">
 		<!-- Set the splash screen background, animated icon, and animation

platform/android/java/editor/src/main/res/values/themes.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-	<style name="GodotEditorTheme" parent="@android:style/Theme.Black.NoTitleBar.Fullscreen">
+	<style name="GodotEditorTheme" parent="@android:style/Theme.DeviceDefault.NoActionBar.Fullscreen">
+		<item name ="android:windowDrawsSystemBarBackgrounds">false</item>
 	</style>
 
 	<style name="GodotEditorSplashScreenTheme" parent="Theme.SplashScreen.IconBackground">