Add default active developers into OWNERS

Bug: 33166666
Test: gerrit uploader
Change-Id: I8161f25b9c1b9a4eae74a7a0e4bdfcff84149d0a
diff --git a/OWNERS b/OWNERS
new file mode 100644
index 0000000..32bf1c3
--- /dev/null
+++ b/OWNERS
@@ -0,0 +1 @@
+iam@google.com