Add OWNERS in external/android-clat

* Owners are selected from top CL approvals or owners.
  They will be suggested to review/approve future CLs.
* OWNERS files are recognized by the new find-owners plugin, see .md files in
  https://gerrit.googlesource.com/plugins/find-owners/+/master/src/main/resources/Documentation/

Test: build/make/tools/checkowners.py -c -v OWNERS
Change-Id: Ied56f2eb0e21a1c61ec67c891d31c837b6bb1b7f
diff --git a/OWNERS b/OWNERS
new file mode 100644
index 0000000..8f0a28b
--- /dev/null
+++ b/OWNERS
@@ -0,0 +1,2 @@
+lorenzo@google.com
+ek@google.com