Update fade event logging to clarify the event type

Unifying fade event logging has the unwanted impact of
stripping out the exact event type information. This
makes reading of logged events harder and may require
additional parsing.

Revert back to using dedicated events for fade out and
fade in. Update them to also log volume shaper information.

Bug: 307354764
Bug: 316634896
Test: atest -c FadeOutManager FadeConfigurations
Change-Id: I53c129395197f1574c2206ffafdd48748d72a0d5