StatusCallback is not sent when dial branch rejects the call

[ghjansen]

Related to issue #2271 and PR #2420.

Scenario:

• Restcomm creates multiple outbound calls through a Dial forking RCML like:

<Response>
  <Dial>
    <Client statusCallback="http://127.0.0.1:8181">bob</Client>
    <Client statusCallback="http://127.0.0.1:8181">alice</Client>
    <Client statusCallback="http://127.0.0.1:8181">steve</Client>
    <Client statusCallback="http://127.0.0.1:8181">scarlet</Client>
    <Client statusCallback="http://127.0.0.1:8181">julia</Client>
  </Dial>
</Response>

• each one of the call branches answers back with SIP 486 (BUSY)

Failure:

• no statusCallback notification is sent at the time each call branch is rejected (5 completed statusCallback notifications should be sent)

[ghjansen]

Solution:
Inclusion of the missing call to method executeStatusCallback(CallbackState.COMPLETED); at the class org.restcomm.connect.telephony.Call.Busy.

Closed via PR #2420 .