Currently we do have wrong bind mount order, due to which /var/log/journal
is shadow mounted with later added /var/log mount.
To prevent this we're inserting new mounts before existing ones
in case where they could shadow mount destination.
Change-Id: Id8cca6d83c75202a273df23be353480366ead156
Closes-Bug: #1895533
(cherry picked from commit 7d7afa4f9adf5fbae93da5fd26c7b91496ace36b)