Add default code reviewers into OWNERS

Bug: 33166666
Test: gerrit uploader
Change-Id: I94cd879fd68962848ebff07d9bcb4f043dfd9606
diff --git a/OWNERS b/OWNERS
new file mode 100644
index 0000000..ebe4345
--- /dev/null
+++ b/OWNERS
@@ -0,0 +1,4 @@
+peteg@google.com
+tobiast@google.com
+paulduffin@google.com
+