Add default code reviewers into OWNERS

Bug: 33166666
Test: gerrit uploader
Change-Id: I62c3a08c7d3a635a6ef4950b36937ed4899642ad
diff --git a/OWNERS b/OWNERS
new file mode 100644
index 0000000..71e50ac
--- /dev/null
+++ b/OWNERS
@@ -0,0 +1,3 @@
+# Default code reviewers picked from top 3 or more developers.
+# Please update this list if you find better candidates.
+include platform/external/libtextclassifier:/OWNERS