screenOrientation - smartphone = PORTRAIT and tablet = DYNAMIC

bools.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <bool name="portrait_only">true</bool>
</resources>

manifest.xml

<activi
            android:name=".MyAmazingActivity"
            android:configChanges="orientation|screenSize"
            android:screenOrientation="behind"/>

MyAmazingActivity

class MyAmazingActivity: AppCompatActivity {
  override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        if (resources.getBoolean(R.bool.portrait_only)) {
            setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT)
        } else {
            setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_SENSOR)
        }
    }
}

sw600dp_bools.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <bool name="portrait_only">false</bool>
</resources>