Poll for accessible driver service, even if process has begun

Author: RenderMichael

dotnet/src/webdriver/DriverService.cs

@@ -239,6 +239,12 @@ public async Task StartAsync()
         {
             if (this.driverServiceProcess != null)
             {
+                bool serviceAvailable = await this.WaitForServiceInitializationAsync().ConfigureAwait(false);
+                if (!serviceAvailable)
+                {
+                    throw new WebDriverException($"Cannot start the driver service on {this.ServiceUrl}");
+                }
+
                 return;
             }