build(Lockdown): Adding lockdown.yml.

Author: arriolac

.github/lockdown.yml

@@ -0,0 +1,37 @@
+# Configuration for Repo Lockdown - https://github.com/dessant/repo-lockdown
+
+# Skip issues and pull requests created before a given timestamp. Timestamp must
+# follow ISO 8601 (`YYYY-MM-DD`). Set to `false` to disable
+skipCreatedBefore: false
+
+# Issues and pull requests with these labels will be ignored. Set to `[]` to disable
+exemptLabels: []
+
+# Comment to post before closing or locking. Set to `false` to disable
+comment: >
+    We are not accepting external contributions at this time. Please see our [README](https://github.com/googlemaps/maps-sdk-for-ios-samples/blob/master/README.md) for more information.
+
+# Label to add before closing or locking. Set to `false` to disable
+label: false
+
+# Close issues and pull requests
+close: true
+
+# Lock issues and pull requests
+lock: true
+
+# Limit to only `issues` or `pulls`
+only: pulls
+
+# Optionally, specify configuration settings just for `issues` or `pulls`
+# issues:
+#   label: wontfix
+
+# pulls:
+#   comment: >
+#     This repository does not accept pull requests, see the README for details.
+#   lock: false
+
+# Repository to extend settings from
+# _extends: repo
+