Add default code reviewers into OWNERS

Bug: 33166666
Test: gerrit uploader
Change-Id: Idefb7d11622e51386c4ee5f5e773ea2c5ff964ca
diff --git a/OWNERS b/OWNERS
new file mode 100644
index 0000000..080f8f8
--- /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.
+jsharkey@android.com
+smain@google.com # for files under res/