Update OWNERS to be more specific

Still to do ... media/OWNERS

Test: Gerrit works as expected
Change-Id: I2645175569b579764d0298641287e56bfabeab9f
diff --git a/tools/OWNERS b/tools/OWNERS
index 6dcb035..f9cb567 100644
--- a/tools/OWNERS
+++ b/tools/OWNERS
@@ -1 +1 @@
-gkasten@android.com
+gkasten@google.com