Add metric fields for Smart Suggestions in Notifications logging.

Add extra data when logging
1. whenever smart replies and actions in notifications become visible,
and
2. whenever a smart action in a notification is clicked.

Documentation:
go/ssin-metrics

Bug: 120767764
Test: tested together with ag/5764960
Change-Id: I7bc735000df9380998e0e4c8f672bca08e8707df