no need to call GrpcEnvironment.Initialize() explicitly

src/csharp/Grpc.IntegrationTesting/InteropClientServerTest.cs

@@ -55,8 +55,6 @@ namespace Grpc.IntegrationTesting
         [TestFixtureSetUp]
         public void Init()
         {
-            GrpcEnvironment.Initialize();
-
             server = new Server();
             server.AddServiceDefinition(TestService.BindService(new TestServiceImpl()));
             int port = server.AddListeningPort(host, Server.PickUnusedPort, TestCredentials.CreateTestServerCredentials());
@@ -74,7 +72,6 @@ namespace Grpc.IntegrationTesting
         public void Cleanup()
         {
             channel.Dispose();
-
             server.ShutdownAsync().Wait();
             GrpcEnvironment.Shutdown();
         }

src/csharp/Grpc.IntegrationTesting/InteropServer.cs

@@ -88,8 +88,6 @@ namespace Grpc.IntegrationTesting
 
         private void Run()
         {
-            GrpcEnvironment.Initialize();
-
             var server = new Server();
             server.AddServiceDefinition(TestService.BindService(new TestServiceImpl()));