Name the agent on every stock line, as a meeting does, where several agents can be audio only: a call's "Audio
only:" reads "Audio only for :". Lines that already name the agent, and a host's own lines, are unchanged.
A reason this version doesn't know reads the meeting's line (AVATAR_NOTICE_UNKNOWN_REASON_TEXT) with it and
the call's (AVATAR_NOTICE_CALL_UNKNOWN_REASON_TEXT) without. Off by default, as in a call.
How AvatarNoticeText words a line.