add option to show Google Maps traffic layer (fixes #19)

app/src/main/java/net/vonforst/evmap/fragment/MapFragment.kt

@@ -331,6 +331,9 @@ class MapFragment : Fragment(), OnMapReadyCallback, MapsActivity.FragmentCallbac
         vm.mapType.observe(viewLifecycleOwner, Observer {
             map?.mapType = it
         })
+        vm.mapTrafficEnabled.observe(viewLifecycleOwner, Observer {
+            map?.isTrafficEnabled = it
+        })
     }
 
     private fun updateBackPressedCallback() {
@@ -443,7 +446,9 @@ class MapFragment : Fragment(), OnMapReadyCallback, MapsActivity.FragmentCallbac
 
     override fun onMapReady(map: GoogleMap) {
         this.map = map
-        map.uiSettings.isTiltGesturesEnabled = false;
+        map.uiSettings.isTiltGesturesEnabled = false
+        map.isIndoorEnabled = false
+        map.uiSettings.isIndoorLevelPickerEnabled = false
         map.setOnCameraIdleListener {
             vm.mapPosition.value = MapPosition(
                 map.projection.visibleRegion.latLngBounds, map.cameraPosition.zoom

app/src/main/java/net/vonforst/evmap/viewmodel/MapViewModel.kt

@@ -144,6 +144,12 @@ class MapViewModel(application: Application, geApiKey: String) : AndroidViewMode
         }
     }
 
+    val mapTrafficEnabled: MutableLiveData<Boolean> by lazy {
+        MutableLiveData<Boolean>().apply {
+            value = false
+        }
+    }
+
     fun setMapType(type: Int) {
         mapType.value = type
     }