Add tags argument to grpc_cc_test and tag tcp_server_posix_test manual.
diff --git a/bazel/grpc_build_system.bzl b/bazel/grpc_build_system.bzl
index 095b159..a56db77 100644
--- a/bazel/grpc_build_system.bzl
+++ b/bazel/grpc_build_system.bzl
@@ -110,7 +110,7 @@
     generate_mocks = generate_mocks,
   )
 
-def grpc_cc_test(name, srcs = [], deps = [], external_deps = [], args = [], data = [], uses_polling = True, language = "C++", size = "medium", timeout = "moderate"):
+def grpc_cc_test(name, srcs = [], deps = [], external_deps = [], args = [], data = [], uses_polling = True, language = "C++", size = "medium", timeout = "moderate", tags = []):
   copts = []
   if language.upper() == "C":
     copts = if_not_windows(["-std=c99"])
@@ -140,6 +140,7 @@
           poller,
           '$(location %s)' % name,
         ] + args['args'],
+        tags = tags,
       )
   else:
     native.cc_test(**args)