Add linux_chromium_chromeos_ozone_rel_ng to CQ.

So ANGLE's Ozone backend gets compiled.

BUG=angleproject:1412

Change-Id: Id4b401f59cd9d3f4dd0b945af67ecc0c9e5d68a2
Reviewed-on: https://chromium-review.googlesource.com/395607
Commit-Queue: Frank Henigman <fjhenigman@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>

infra/config/cq.cfg

@@ -21,6 +21,10 @@ verifiers {
       builders { name: "win_angle_x64_rel_ng" }
       builders { name: "win_angle_x64_dbg_ng" }
     }
+    buckets {
+      name: "master.tryserver.chromium.linux"
+      builders { name: "linux_chromium_chromeos_ozone_rel_ng" }
+    }
     buckets {
       name: "master.tryserver.chromium.win"
       builders { name: "win_clang" }