address feedback

Author: parthea

packages/gapic-generator/WORKSPACE

@@ -116,9 +116,8 @@ http_archive(
     sha256 = _grpc_sha256,
     strip_prefix = "grpc-{}".format(_grpc_version),
     urls = ["https://github.com/grpc/grpc/archive/v{}.zip".format(_grpc_version)],
-    patch_cmds = [
-        "python3 -c \"f='src/core/lib/surface/legacy_channel.cc'; c=open(f).read(); open(f,'w').write(c.replace('args.arena_init_function = arena_init_function;', 'if (arena_init_function.has_value()) { args.arena_init_function.emplace(*arena_init_function); }')) if 'args.arena_init_function = arena_init_function;' in c else None\""
-    ],
+    patches = ["//third_party:grpc_legacy_channel.patch"],
+    patch_args = ["-p1"],
 )
 load("@com_github_grpc_grpc//bazel:grpc_deps.bzl", "grpc_deps")
 grpc_deps()

packages/gapic-generator/repositories.bzl

@@ -27,9 +27,8 @@ def gapic_generator_python():
         sha256 = _grpc_sha256,
         strip_prefix = "grpc-{}".format(_grpc_version),
         url = "https://github.com/grpc/grpc/archive/v{}.zip".format(_grpc_version),
-        patch_cmds = [
-            "python3 -c \"f='src/core/lib/surface/legacy_channel.cc'; c=open(f).read(); open(f,'w').write(c.replace('args.arena_init_function = arena_init_function;', 'if (arena_init_function.has_value()) { args.arena_init_function.emplace(*arena_init_function); }')) if 'args.arena_init_function = arena_init_function;' in c else None\""
-        ],
+        patches = ["@gapic_generator_python//third_party:grpc_legacy_channel.patch"],
+        patch_args = ["-p1"],
     )
 
     _maybe(