Add a dbus constant for PrioritizeArcInstance()

BUG=chrome-os-partner:56555
TEST=None

Change-Id: I158f35744ced305ce1555a0130df0a281203bad3
Reviewed-on: https://chromium-review.googlesource.com/383074
Commit-Ready: Yusuke Sato <yusukes@chromium.org>
Tested-by: Yusuke Sato <yusukes@chromium.org>
Reviewed-by: Dan Erat <derat@chromium.org>
(cherry picked from commit 832123293273d615fdf6a1654fdd5f12d3730ec0)
Reviewed-on: https://chromium-review.googlesource.com/385041
Reviewed-by: Yusuke Sato <yusukes@chromium.org>
Commit-Queue: Yusuke Sato <yusukes@chromium.org>
1 file changed