make_statusbar_transparent.txt

fun AppCompatActivity.setStatusBarTransparent() {
    window.decorView.systemUiVisibility = window.decorView.systemUiVisibility or View.SYSTEM_UI_FLAG_LAYOUT_STABLE or View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
    setWindowFlag(this, WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS, false)
    window.statusBarColor = Color.TRANSPARENT
}

private fun setWindowFlag(activity: Activity, bits: Int, on: Boolean) {
    val win = activity.window
    val winParams = win.attributes
    if (on) {
        winParams.flags = winParams.flags or bits
    } else {
        winParams.flags = winParams.flags and bits.inv()
    }
    win.attributes = winParams
}

// If you want for Splash screen to be transparent, you can create a new style and apply to your applicaion in Manifest(I did it as a full screen improvisation):
 <application
        android:name="package_name">
        android:theme="@style/LaunchScreenTheme"
        ....</application>

<style name="LaunchScreenTheme" parent="AppTheme">
        <item name="android:windowActionBarOverlay">false</item>
        <item name="android:windowTranslucentStatus">false</item>
        <item name="android:windowFullscreen">true</item>
        <item name="android:windowBackground">@drawable/preview_screen</item>
        <item name="windowActionBar">false</item>
</style> 

// And in MainActivity, apply your App theme :)
 override fun onCreate(savedInstanceState: Bundle?) {
        setTheme(R.style.AppTheme)
        super.onCreate(savedInstanceState)
        setStatusBarTransparent()
 }