update user profile api to return user locale

refs PS-1725

test plan:
  1. make the user profile api call
  2. validate the new locale key and values are returned
  3. go to your settings and change your locale
  4. make sure the new locale is returned via api
Change-Id: I0a0ebae6c227b74e1f8c149dcd638aa735edbea8
Reviewed-on: https://gerrit.instructure.com/37099
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Jon Jensen <jon@instructure.com>
Product-Review: Jake Sorce <jake@instructure.com>
QA-Review: Jake Sorce <jake@instructure.com>
Tested-by: Jake Sorce <jake@instructure.com>