Handle charging state separately from temporary parole

Don't use the parole state to deal with the plugged-in trigger.
Otherwise standby apps will only be paroled for a few minutes
after plugging in to charge and not the entire duration.

Use a different intent for charging state, since the CHARGING
intent takes several seconds to be received.

A refactor some time ago changed the charging state behavior
that caused this regression.

Bug: 31399882
Change-Id: Ic036de5e136b3151b225473d0c3f440adb3b48e7