Revert "Allow conversation channels to inherit canBypassDnd from their parent."

This reverts commit c6ca8afec1ee153c6e8bc733d98d23be7c080643.

Reason for revert: actually we don't want to do this; see comments on original commit

Change-Id: I4495bb3ae1cf0be0997efdbdaf150c2a4f63c450
3 files changed