[Settings] Learn more link should be removed when not supported.

Learn more wording with link only help people when configured.
When no link available, these wording had better removed to avoid from
confusing people.

Bug: 159510116
Test: manual
Merged-In: I36b74b2b4586546090fb88562e8f4f052a877709
Change-Id: If7061e0be201b2f98964a7b0eec42cc17cb11ae3