The change action API provides informative descriptions of the actions.
Problematically
- For action buttons, these were provided in native tooltips that are
hard to discover.
- For overflow actions, the context was not provided at all.
Include the context information in easily discoverable gr-tooltips for
all actions whether they're button or overflow.
Feature: Issue 6781
Change-Id: I667fe59578b57ffc88c87e77df4be991875425a4
80af0b7505