Currency symbol keys are more aware of locale

* Locale is one of EU, main currency is Euro, and more currencies are
  Pound, Yen and Dollar (plus Cent on 10" tablet)
* Locale is GB, main currency is Pound, and more currencies are
  Euro, Yen and Dollar (plus Cent on 10" tablet)
* Locale has special currency symbol such as Hebrew,
  main currency is the one, and more currencies are
  Pound, Euro, Dollar (plus Cent on 10" tablet)
* Other than these, main currency is Dollar, and more currencies are
  Pound, Cent, Euro (plus Yen on 10" tablet)

Bug: 5281876
Change-Id: I548dc663bafdb3b3f717f4328fda8dfcbafca2df