Add logging for smart replies and actions.

Log (using TRON)
1. when smart replies and actions are shown in a notification, and
2. when a smart action is clicked.

Bug: 120767764
Test: manual - use logcat to ensure we log the correct values when a
notification is expanded / smart action is clicked.

Change-Id: I85dbc3ee355997142ad71b7b67a759e8fede94b6