Add default code reviewers into OWNERS

Bug: 33166666
Test: gerrit uploader
Change-Id: I12e71475020f28ce997c738bf4edccd7048d70b4
diff --git a/OWNERS b/OWNERS
new file mode 100644
index 0000000..61227ad
--- /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.
+ccross@android.com
+dwillemsen@google.com