Add extra owners for file `core/tasks/art-host-tests.mk`.

Test: build/make/tools/checkowners.py -c build/make/core/tasks/OWNERS
Bug: 169111770
Change-Id: I6dbbabd35386d806a786e1d895070bb2c19fa2c6
diff --git a/core/tasks/OWNERS b/core/tasks/OWNERS
new file mode 100644
index 0000000..594930d
--- /dev/null
+++ b/core/tasks/OWNERS
@@ -0,0 +1 @@
+per-file art-host-tests.mk = dshi@google.com,dsrbecky@google.com,jdesprez@google.com,rpl@google.com