Revert "Remove abandoned implementation."

Revert submission 3242160-remove-messaging-package

Reason for revert: Droidmonitor created revert due to b/364617310, b/364626927, b/364617560

Reverted changes: /q/submissionid:3241481-remove-messaging-package

This reverts commit 93b5e63726ab8f47a8266ed1cccf7c9c281bf0e0.

Change-Id: I182cbf1758988d9a4950d39354266a5fb3aaabce
diff --git a/OWNERS b/OWNERS
new file mode 100644
index 0000000..f4ccae0
--- /dev/null
+++ b/OWNERS
@@ -0,0 +1,4 @@
+# Default code reviewers picked from top 3 or more developers.
+# Please update this list if you find better candidates.
+tomtaylor@google.com
+rtenneti@google.com