Modify Comparator in ZonePicker

The previous method "compareTo" isn't locale-sensitive, it cannot
sort the String in some other languages. So Collator is recommended
to be applyed here.

Bug: Sort doesn't work in some languages.
Test: make RunSettingsRoboTests -j40 ROBOTEST_FILTER=ZonePickerComparatorTest

Change-Id: Id107ab938cceefc77f9fb6918a0445fc92a0fcb7
Signed-off-by: tiansiming <tiansiming@xiaomi.com>