do not allow syncing checklist files with the note itself

app/src/main/kotlin/com/simplemobiletools/notes/pro/activities/MainActivity.kt

@@ -349,11 +349,22 @@ class MainActivity : SimpleActivity() {
     private fun openFile() {
         FilePickerDialog(this, canAddShowHiddenButton = true) {
             openFile(it, true) {
+                Thread {
+                    val fileText = it.readText().trim()
+                    val checklistItems = fileText.parseChecklistItems()
+                    if (checklistItems != null) {
+                        val note = Note(null, it.absolutePath.getFilenameFromPath(), fileText, TYPE_CHECKLIST)
+                        addNewNote(note)
+                    } else {
+                        runOnUiThread {
                             OpenFileDialog(this, it.path) {
                                 addNewNote(it)
                             }
                         }
                     }
+                }.start()
+            }
+        }
     }
 
     private fun openFile(path: String, checkTitle: Boolean, onChecksPassed: (file: File) -> Unit) {

app/src/main/kotlin/com/simplemobiletools/notes/pro/extensions/String.kt

@@ -0,0 +1,16 @@
+package com.simplemobiletools.notes.pro.extensions
+
+import com.google.gson.Gson
+import com.google.gson.reflect.TypeToken
+import com.simplemobiletools.notes.pro.models.ChecklistItem
+
+fun String.parseChecklistItems(): ArrayList<ChecklistItem>? {
+    if (startsWith("[{") && endsWith("}]")) {
+        try {
+            val checklistItemType = object : TypeToken<List<ChecklistItem>>() {}.type
+            return Gson().fromJson<ArrayList<ChecklistItem>>(this, checklistItemType) ?: ArrayList(1)
+        } catch (e: Exception) {
+        }
+    }
+    return null
+}