Android/Kotlin activity with Password input

MainActivity.kt

package org.asheesh.bottomnavigationactivity

import android.os.Bundle
import android.text.InputType
import android.text.method.PasswordTransformationMethod
import android.view.Gravity
import android.view.View
import android.widget.EditText
import android.widget.RelativeLayout
import android.widget.TextView
import androidx.appcompat.app.AppCompatActivity


class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        val relativeLayout = RelativeLayout(this)
        val tv1 = TextView(this)
        tv1.text = "tv1 is here"
        // Setting an ID is mandatory.
        // Setting an ID is mandatory.
        tv1.id = View.generateViewId()
        relativeLayout.addView(tv1)

        val password = EditText(this)
        password.gravity = Gravity.CENTER
        password.hint = "Password"
        password.inputType = InputType.TYPE_CLASS_TEXT or InputType.TYPE_TEXT_VARIATION_PASSWORD

        password.transformationMethod = PasswordTransformationMethod()
        relativeLayout.addView(password)

        this.setContentView(relativeLayout)

    }
}