[devserver] Add push_to_device_zip artifact

(Android CL for building push_to_device.zip : ag/4402917)

BUG=b:37257167
TEST=provision_CheetsUpdate pointing to local devserver
Change-Id: I9c4efc1a26f928bd371b25bf094c2576e6ef9951
Reviewed-on: https://chromium-review.googlesource.com/1113265
Commit-Ready: Qijiang Fan <fqj@google.com>
Tested-by: Satoshi Niwa <niwa@chromium.org>
Tested-by: Qijiang Fan <fqj@google.com>
Reviewed-by: Luis Hector Chavez <lhchavez@chromium.org>
diff --git a/artifact_info.py b/artifact_info.py
index 2eb9070..46c26ec 100644
--- a/artifact_info.py
+++ b/artifact_info.py
@@ -129,6 +129,9 @@
 # Zip file containing DTB for emulators
 ANDROID_DTB_ZIP = 'dtb'
 
+# Zip file containing push_to_device.py and tools it depends on
+ANDROID_PUSH_TO_DEVICE_ZIP = 'push_to_device_zip'
+
 # In general, downloading one artifact usually indicates that the caller will
 # want to download other artifacts later. The following map explicitly defines
 # this relationship. Specifically: