Moving the pre-recorded greeting toggle to the softphone settings.

We currently have a toggle option when starting a FastTrack call that allows you to control whether the pre-recorded voice greetings are played on the call or not. 

We have removed this toggle from the call form and move it into the softphone settings instead.

The reason for making this change is that we are planning to introduce product changes that allow calls to be created outside of the form (e.g. through an API or via call queue) so we need to manage the pre-recorded voice greeting setting in a central place (not in the create call form). 

INSTRUCTIONS: When this change releases you will need to check your preferred setting in the softphone settings. The setting will apply to all calls and can be changed anytime.