Remove suggestion UI v1 codes.

- remove the check for feature flag for suggestion UI v2 and switch to
use the v2 codes.
- remove all code related to v1 of suggestion UI

Fixes: 70573674
Test: make RunSettingsRoboTests

Change-Id: I99ab318c1c0192508a9c5e9e708e86319120d55b
29 files changed