Revert "Reuse the definition already in the bazel/ directory"

Turns out that putting this in the main build definition starklark file
means that our users will also incur a dependency on the repo rule.
That's no bueno.

This reverts commit 78e443b4f6.

bazel/custom_exec_properties.bzl

@@ -0,0 +1,18 @@
+# Copyright 2019 The gRPC authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+load("@grpc_custom_exec_properties//:constants.bzl", _LARGE_MACHINE = "LARGE_MACHINE")
+
+LARGE_MACHINE = _LARGE_MACHINE

bazel/grpc_build_system.bzl

@@ -26,7 +26,6 @@
 load("//bazel:cc_grpc_library.bzl", "cc_grpc_library")
 load("@upb//bazel:upb_proto_library.bzl", "upb_proto_library")
 load("@build_bazel_rules_apple//apple:ios.bzl", "ios_unit_test")
-load("@grpc_custom_exec_properties//:constants.bzl", _LARGE_MACHINE = "LARGE_MACHINE")
 
 
 # The set of pollers to test against if a test exercises polling
@@ -343,4 +342,3 @@ def python_config_settings():
         flag_values = {"@bazel_tools//tools/python:python_version": "PY3"},
     )
 
-LARGE_MACHINE = _LARGE_MACHINE

test/core/gprpp/BUILD

@@ -12,7 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-load("//bazel:grpc_build_system.bzl", "grpc_cc_library", "grpc_cc_test", "grpc_cc_binary", "grpc_package", "LARGE_MACHINE")
+load("//bazel:grpc_build_system.bzl", "grpc_cc_library", "grpc_cc_test", "grpc_cc_binary", "grpc_package")
+load("//bazel:custom_exec_properties.bzl", "LARGE_MACHINE")
 
 licenses(["notice"])  # Apache v2
 

test/core/iomgr/BUILD

@@ -12,7 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-load("//bazel:grpc_build_system.bzl", "grpc_cc_library", "grpc_cc_test", "grpc_cc_binary", "grpc_package", "LARGE_MACHINE")
+load("//bazel:grpc_build_system.bzl", "grpc_cc_library", "grpc_cc_test", "grpc_cc_binary", "grpc_package")
+load("//bazel:custom_exec_properties.bzl", "LARGE_MACHINE")
 
 licenses(["notice"])  # Apache v2
 

test/cpp/qps/BUILD

@@ -14,8 +14,9 @@
 
 licenses(["notice"])  # Apache v2
 
-load("//bazel:grpc_build_system.bzl", "grpc_cc_test", "grpc_cc_library", "grpc_cc_binary", "grpc_package", "LARGE_MACHINE")
+load("//bazel:grpc_build_system.bzl", "grpc_cc_test", "grpc_cc_library", "grpc_cc_binary", "grpc_package")
 load("//test/cpp/qps:qps_benchmark_script.bzl", "qps_json_driver_batch", "json_run_localhost_batch")
+load("//bazel:custom_exec_properties.bzl", "LARGE_MACHINE")
 
 grpc_package(name = "test/cpp/qps")