Add snippet markers

Author: ithinkihaveacat

wear/src/main/java/com/example/wear/snippets/tile/Tile.kt

@@ -29,6 +29,7 @@ import com.google.common.util.concurrent.Futures
 
 private const val RESOURCES_VERSION = "1"
 
+// [START android_wear_tile_mytileservice]
 class MyTileService : TileService() {
 
     override fun onTileRequest(requestParams: RequestBuilders.TileRequest) =
@@ -48,4 +49,5 @@ class MyTileService : TileService() {
             .build()
         )
 
-}
+}
+// [END android_wear_tile_mytileservice]