Log cleanup: remove unnecessary logging for suggestions

- Remove show_suggestion logging in DashboardAdapater. Showing
  suggestion is logged inside SuggestionAdapter during onBind.
- Remove hide_suggestion logging. It's not used by anyone.
- Move SuggestionLogHelper into SuggestionFeatureProvider

Bug: 65065268
Test: robotests
Change-Id: I1e7929d739b79527d2ae01c25177676f6be6ddff