Код-ревью: найди утечки памяти

class MapActivity : AppCompatActivity(), LocationListener {

    companion object {
        var lastActivity: MapActivity? = null
    }

    private val handler = Handler(Looper.getMainLooper())

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_map)
        lastActivity = this
        val lm = getSystemService(LOCATION_SERVICE) as LocationManager
        lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000L, 0f, this)
        handler.postDelayed({ showHint() }, 30_000)
        GlobalScope.launch {
            val places = api.loadPlaces()
            withContext(Dispatchers.Main) { renderPlaces(places) }
        }
        Analytics.init(this)
    }

    override fun onLocationChanged(location: Location) {
        findViewById<TextView>(R.id.coords).text = "${location.latitude}"
    }
}