Finalmente, consegui exibir o mapa. Agora, quero mostrar minha localização atual. Tentei usar esses códigos, mas não funcionou quando clicou no botão minha localização no canto superior direito.

AndroidManifest.xml

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission android:name="com.example.hp.testmap.MAPS_RECEIVE"></uses-permission>
<uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />

<permission
    android:name="com.example.hp.testmap.permission.MAPS_RECEIVE"
    android:protectionLevel="signature"/>

    <uses-feature
        android:glEsVersion="0x00020000"
        android:required="true"/>

MapsActivity.java

public void onMapReady(GoogleMap googleMap) {
    mMap = googleMap;
    mMap.setMyLocationEnabled(true);
   if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {

       LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

       Criteria criteria = new Criteria();

       String provider = locationManager.getBestProvider(criteria, true);

       Location myLocation = locationManager.getLastKnownLocation(provider);

       mMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);

        double latitude = myLocation.getLatitude();

        double longitude = myLocation.getLongitude();

        LatLng latLng = new LatLng(latitude, longitude);

        mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));

        mMap.animateCamera(CameraUpdateFactory.zoomTo(20));
        return;
    }

}