Fix NPE in startOutoingCall with no phoneAccount.

When a SIP account is added but not enabled, startOutgoingCall cannot
determine a valid phoneAccount to use for initiating the call. This
results in a NPE when trying to change the state of the call to
CONNECTING. So, sending a "no-handle" tag when phoneAccount is null when
invoking setState.

BUG: 21887733
Change-Id: I84b54b48c7e937e5766ae58e52489b708898025b