sm8150-common: sepolicy: Resolve some ugly dashd issues

* Since a certain funny mod does some unexpected
  changes to rootfs, which essentially resets
  /sbin/dashd label back to u:object_r:rootfs:s0,
  the dashd cannot be started anymore.
* This change syncs attributes and allows init to
  execute files with u:object_r:rootfs:s0 context
  as u:object_r:dashd:s0 using seclabel service
  option just like OnePlus does on stock.
* We are also reverting bea94bd6 just because it's
  not needed anymore and dropping /sbin/dashd fs
  label just so that we can easier spot this issue
  if it'd ever happen again.

Change-Id: I98b376a66836aae036b8e41bb0300ce0d926f4c2