message: Add internal unit test for gcs config ops to check that it retrieves the correct file system depending on the build time options.
diff: @@ -100,6 +100,38 @@ cc_library(
  alwayslink = 1,
  )
  +cc_library(
  + name = "gcs_file_system_disabled",
  + srcs = ["gcs_file_system.cc"],
  + hdrs = ["gcs_file_system.h"],
  + copts = tf_copts() + [
  + "-DTPU_GCS_FS",
  + "-DPLATFORM_CLOUD_TPU",
  + ],
  + linkstatic = 1, # Needed since alwayslink is broken in bazel b/27630669
  + visibility = ["//visibility:public"],
  + deps = [
  + ":compute_engine_metadata_client",
  + ":compute_engine_zone_provider",
  + ":curl_http_request",
  + ":expiring_lru_cache",
  + ":file_block_cache",
  + ":gcs_dns_cache",
  + ":gcs_throttle",
  + ":google_auth_provider",
  + ":http_request",
  + ":ram_file_block_cache",
  + ":retrying_file_system",
  + ":retrying_utils",
  + ":time_util",
  + "//tensorflow/core:framework_headers_lib",
  + "//tensorflow/core:lib",
  + "//tensorflow/core:lib_internal",
  + "@jsoncpp_git//:jsoncpp",
  + ],
  + alwayslink = 1,
  +)
  +
  cc_library(
  name = "http_request",
  hdrs = ["http_request.h"],
  