Fix regression for answering a ringing call when there are 2 calls already.

In the case where there is already a held and active call and a new
incoming call is being answered, previous logic was to disconnect the
held call and then hold the previous foreground call before answering
the incoming call.

This CL fixes a regression in that functionality.

Test: Manual
Bug: 74939079
Change-Id: I150fa51cd0e67d5e39e9cf09268c50ba66d570c2