Add default code reviewers into OWNERS

Bug: 33166666
Test: gerrit uploader
Change-Id: I764a14f53094c561a5a9672a559fec70a84c735f
diff --git a/OWNERS b/OWNERS
new file mode 100644
index 0000000..ffe9515
--- /dev/null
+++ b/OWNERS
@@ -0,0 +1,5 @@
+# Default code reviewers picked from top 3 or more developers.
+# Please update this list if you find better candidates.
+szuweilin@google.com
+bowgotsai@google.com
+hridya@google.com