Cannot access 'TAG': it is invisible (private in supertype) in 'AppCompatActivity' - android-activity

Question

I am a beginner in android programming. I'm currently using android studio 3.2.1.
I am trying to monitor the different states of an android activity in log. I have written the code shown below, but I keep receiving the error message:
Cannot access 'TAG': it is invisible (private in supertype) in 'AppCompatActivity'.
Even after searching, I cannot figure the error. Can some one help?
Code:
package com.cooperation.bestech.test1
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.util.Log;
class MainActivity : AppCompatActivity() {
private static final String TAG = "MyMessage";
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
Log.i(TAG, "onCreate");
}
override fun onStart() {
super.onStart()
Log.i(TAG, "onStart");
}
override fun onPause() {
super.onPause()
Log.i(TAG, "onPause");
}
override fun onResume() {
super.onResume()
Log.i(TAG, "onResume");
}
override fun onStop() {
super.onStop()
Log.i(TAG, "onStop");
}
override fun onRestart() {
super.onRestart()
Log.i(TAG, "onRestart");
}
override fun onDestroy() {
super.onDestroy()
Log.i(TAG, "onDestroy");
}
override fun onSaveInstanceState(outState: Bundle?) {
super.onSaveInstanceState(outState)
Log.i(TAG, "onSaveInstanceState");
}
override fun onRestoreInstanceState(savedInstanceState: Bundle?) {
super.onRestoreInstanceState(savedInstanceState)
Log.i(TAG, "onRestoreInstanceState");
}
}

Answer 1

Since the original question is written in Kotlin (from comment), ignore the request of "launch Java project instead of the default Kotlin" may be a better solution.
And, applying the correct way to declare and assign a variable, your code segment should be like this:
class MainActivity : AppCompatActivity() {
val TAG = "MyMessage"

Answer 2

import android.content.ContentValues.TAG

Answer 3

Seems you are using Kotlin.So you need to define TAG in kotlin way:
In Kotlin constants located in the companion object:
class MyClass {
companion object {
private val TAG = "ClassName"
}
}