Add SettingsMultiSelectListPreference style

There is no OK and CANCEL button when changing APN Bearer.
To fix this issue, OK and CANCEL button should be added to
SettingsMultiSelectListPreference style.

Fixes: 66928311
Test: manual - Add a new APN and tap Bearer

Change-Id: I2b5719a7c1fdb721b15308e0eef7db3e6398e097