When migrating from old snapshots to magnesium format we have to
make sure we also legacy uint mapped values, so that after recovery
we end up with proper types being present.
JIRA: CONTROLLER-1919
Change-Id: I86ee49efee0d6c0519680197ea3e3985b1566e0c Signed-off-by: Robert Varga <robert.varga@pantheon.tech>