Telephony Test: Fix bug in _phone_number_remove_prefix

1. If input number is None, return <None>, <None>
2. If no country code or prefix, return <input number>, <None>

Bug: 29058236
Change-Id: I0a8ced81e8922be35383428156469dec2ef97d37
1 file changed
tree: d79fe18b4632b2d4a2ebfe2c0cb4b61e55a667af
  1. acts/