P-CSCF route header not present in INVITE when outbound proxy is used.

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Register IMSDroid to IMS network. Send service route header in 200 OK to 
REGISTER with S-CSCF IP.
2. Initiate a call.
3. Only S-CSCF route header is seen in the initial INVITE.

What is the expected output? What do you see instead?
There should be a 2 route headers in intial INVITE (P-CSCF and S-CSCF route 
headers.)

What version of the product are you using? On what operating system?
IMSDROID/v2.548.870 on Android

Please provide any additional information below.

MY S-CSCF IP: 172.26.192.111:9999
MY P-CSCF IP: 172.26.192.111:2323

SIP/2.0 200 OK
Via: SIP/2.0/UDP 
172.26.195.112:5060;rport=5060;branch=z9hG4bKPja79bd6fba74e47db855c12f1d624d9af
From: <sip:6199716004@172.26.192.111>;tag=87deb27a1fcb465a8062540fa9445b62
To: <sip:6199716004@172.26.192.111>;tag=d31a247ab76ad1b8a9be7359c1254aa8.1a9a
Call-ID: 870f8ab956e04a609d93748020b8f186
CSeq: 22013 REGISTER
Service-Route: <sip:172.26.192.111:9999;lr>
Contact: <sip:6199716004@172.26.195.112:5060;ob>;expires=300
Server: IMS-Quest
Content-Length: 0

INVITE sip:6199716004@172.26.192.111:2323 SIP/2.0
Via: SIP/2.0/UDP 172.26.195.59:60148;branch=z9hG4bK1114351561;rport
From: <sip:6199716003@172.26.192.111:2323>;tag=61102545
To: <sip:6199716004@172.26.192.111:2323>
Contact: 
<sip:6199716003@172.26.195.59:60148;transport=udp>;+g.oma.sip-im;language="en,fr
";+g.3gpp.icsi-ref="urn%3Aurn-7%3A3gpp-service.ims.icsi.mmtel"
Call-ID: 4df5a8d8-1a50-e98a-4074-5260ffeb5057
CSeq: 1150396027 INVITE
Content-Type: application/sdp
Content-Length: 464
Max-Forwards: 70
Route: <sip:172.26.192.111:9999;lr>
Accept-Contact: *;+g.3gpp.icsi-ref="urn%3Aurn-7%3A3gpp-service.ims.icsi.mmtel"
P-Preferred-Service: urn:urn-7:3gpp-service.ims.icsi.mmtel
Allow: INVITE, ACK, CANCEL, BYE, MESSAGE, OPTIONS, NOTIFY, PRACK, UPDATE, REFER
Privacy: none
P-Access-Network-Info: ADSL;utran-cell-id-3gpp=00000000
User-Agent: IM-client/OMA1.0 android-ngn-stack/v2.548.870 (doubango r870 - 
LT18i)
Supported: 100rel

Original issue reported on code.google.com by ankur.za...@gmail.com on 19 Apr 2013 at 5:26