Update world cities

Bug: 25931904
Bug: 25694200

This update does two things:

1) The format for storing cities discards storing ID, city name and
timezone ID in 3 parallel arrays. Now, all available IDs are stored in
a single untranslatable array. All corresponding translation entries
use the id as the resource name.

2) About 50ish new cities were added to guarantee at least one
location from each country in the world can be located in the list.

Change-Id: I501cc171f47559f8949bede357f9027fe49d0535