TeleService: Add support for IP call prefix

Add a preference screen to edit IP call prefix, and add the
prefix when MO a IP call.

Change-Id: I8c30799d06702eda35c32260998cf72259b7e3d4
TeleService: fix no "speed dial" item in call setting

Add the preference screen of speed dial setting in
call_feature_setting.xml and call_feature_setting_msim.xml

Change-Id: I7a952c9dbd19523e0987483aaaa253d73bcc3262
CRs-Fixed: 727177
TeleService: Add support for ip call prefix

Add a preference screen to edit IP call prefix in
MSimCallFeaturesSubSetting, and add the
prefix when MO a IP call.

Change-Id: I7f823352dcdcdf6ca4c68e9b7ed02c0c3aeb8caf