In order to avoid layering violation, LocaleList needs to be moved from
android.util package to android.os package [1]. This CL follows up that
package change.
No behavior change is intended.
[1]: Ia8de2ee9df3dd0a42b1fe84574439519b680fe18
Bug: 28819696
Change-Id: Ie795c191e299358c7c463693823f309ce61cc985