SettingsProvider: Allow accessing LineageSettings via settings command

This patch allows the settings command line tool to be used with
the LineageSettings provider by passing in --lineage

Co-authored-by: LuK1337 <priv.luk@gmail.com>
Co-authored-by: Sam Mortimer <sam@mortimer.me.uk>
Change-Id: Ie0906c9957e9de8418164d7cc84983d57fa4a015