The keys are identical, and the values nearly so, this will make everyone's life easier.

Test: git grep 'Tether(Down|Up)stream4(Key|Value)' finds nothing
  (note this requires follow up commits)
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Ifbff2c617ac5834ea80f827eaf89ca81e862baec