Fixed an issue where the reply icon was disabled

Because it was disabled by an earlier update, a subsequent update
needs to enable the reply icon again, as the pending intent
might be valid again.

Change-Id: Ic562b399184e37c3870e1da7dc5d15baca43dc54
Fixes: 80250615
Test: add multiple messages where each one cancels the previous pendinging intent, observe clickable reply icon