<NME> .repo-metadata.json
<BEF> ADDFILE
<MSG> Update google-cloud-security_center synth.py (#3236)

* Add .repo-metadata.json.
* Update synth.py.
  * Add copy of default templates.
  * Add AUTHENTICATION.md to files lists.
<DFF> @@ -0,0 +1,6 @@
+{
+  "distribution_name": "google-cloud-security_center",
+  "module_name": "SecurityCenter",
+  "module_name_credentials": "SecurityCenter::V1",
+  "env_var_prefix": "SECURITY_CENTER"
+}
\ No newline at end of file

{'addition_count': 6, 'commit_subject': 'Update google-cloud-security_center synth.py (#3236)', 'deletion_count': 0, 'file_extension': '.json', 'lang': 'repo-metadata', 'license': 'apache-2.0', 'repo_name': 'googleapis/google-cloud-ruby'}