update the included folders list after adding one

app/src/main/kotlin/com/simplemobiletools/gallery/activities/IncludedFoldersActivity.kt

@@ -56,6 +56,7 @@ class IncludedFoldersActivity : SimpleActivity() {
     private fun addIncludedFolder() {
         FilePickerDialog(this, pickFile = false, showHidden = config.showHiddenFolders) {
             config.addIncludedFolder(it)
+            updateIncludedFolders()
             scanPath(it) {}
         }
     }