Dialer: Fix sound settings not sticking

* With the switch to device protected storage we have to let the
  PreferenceManager know that we want to use it before adding the
  preferences
* Currently, switching any toggle of the vibration ones and re-entering
  the settings shows that the setting does not stay active

Change-Id: I9c1b13d307cb398cedbdf359544d695e090827f7
(cherry picked from commit 328c8539)