delete db after latest update

app/src/main/kotlin/com/simplemobiletools/smsmessenger/activities/MainActivity.kt

@@ -80,6 +80,13 @@ class MainActivity : SimpleActivity() {
                 startActivityForResult(intent, MAKE_DEFAULT_APP_REQUEST)
             }
         }
+
+        if (!config.wasDbCleared) {
+            ensureBackgroundThread {
+                messagesDB.deleteAll()
+            }
+            config.wasDbCleared
+        }
     }
 
     override fun onResume() {

app/src/main/kotlin/com/simplemobiletools/smsmessenger/helpers/Config.kt

@@ -75,4 +75,8 @@ class Config(context: Context) : BaseConfig(context) {
     var importMms: Boolean
         get() = prefs.getBoolean(IMPORT_MMS, true)
         set(importMms) = prefs.edit().putBoolean(IMPORT_MMS, importMms).apply()
+
+    var wasDbCleared: Boolean
+        get() = prefs.getBoolean(WAS_DB_CLEARED, false)
+        set(wasDbCleared) = prefs.edit().putBoolean(WAS_DB_CLEARED, wasDbCleared).apply()
 }

app/src/main/kotlin/com/simplemobiletools/smsmessenger/helpers/Constants.kt

@@ -25,6 +25,7 @@ const val EXPORT_MIME_TYPE = "application/json"
 const val EXPORT_FILE_EXT = ".json"
 const val IMPORT_SMS = "import_sms"
 const val IMPORT_MMS = "import_mms"
+const val WAS_DB_CLEARED = "was_db_cleared"
 
 private const val PATH = "com.simplemobiletools.smsmessenger.action."
 const val MARK_AS_READ = PATH + "mark_as_read"

app/src/main/kotlin/com/simplemobiletools/smsmessenger/interfaces/MessagesDao.kt

@@ -43,4 +43,7 @@ interface MessagesDao {
 
     @Query("DELETE FROM messages WHERE thread_id = :threadId")
     fun deleteThreadMessages(threadId: Long)
+
+    @Query("DELETE FROM messages")
+    fun deleteAll()
 }