Fix TelecomManager.isVoicemailNumber

Provide an overload of PhoneNumberUtil.isVoiceMailNumber that
takes a context to prevent an NPE.

This does not fix PhoneNumberUtil.isVoicemailNumber(String number),
that will require a follow up CL.

Bug: 22184528
Change-Id: I300b70948e5ff7230989bb887ad17e222c61685d
1 file changed