json_project_writer: Output response_file_contents for action and action_for_each

Add response_file_contents as a property of the action
and action_for_each targets.

Bug: gn:84
Change-Id: I55eba6411013c6edaaac86331a2550078ac04821
Reviewed-on: https://gn-review.googlesource.com/c/gn/+/5100
Reviewed-by: Brett Wilson <brettw@google.com>
Commit-Queue: Brett Wilson <brettw@google.com>
diff --git a/AUTHORS b/AUTHORS
index fe152fd..417cc5f 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -12,6 +12,7 @@
 IBM Inc. <*@*.ibm.com>
 Loongson Technology Corporation Limited. <*@loongson.cn>
 MIPS Technologies, Inc. <*@mips.com>
+NVIDIA Corporation <*@nvidia.com>
 Opera Software ASA <*@opera.com>
 The Chromium Authors <*@chromium.org>
 Vewd Software AS <*@vewd.com>