More audio use case enhacements

- Use TW's "Call Main Mic" for "Speaker DMIC Endfire".
  - Resolves speakerphone echo by using only the main (bottom) mic.

- Clone "Handset" to "Line", as audio-caf uses "Line" by default now.
  - Also matches TW's "Main Mic".
Remove 7 Step Incall Volume Fix