tree 364788179909a427cda113bd2611ed464bfa8de3
parent c724f2fba330da275f46586aeb5f0ae7bd2fae99
author Hung-ying Tyan <tyanh@google.com> 1292843304 +0800
committer Hung-ying Tyan <tyanh@google.com> 1292903463 +0800

Check if VoIP API is supported in SipManager.

This is to make SipManager.isVoipSupported() effective.
Also add NPE check now that we may return null SipAudioCall when VOIP is not
supported.

Bug: 3251016

Change-Id: Icd551123499f55eef190743b90980922893c4a13