Make SwiftScenarioTest methods public

An earlier refactoring (commit
0d49411dbb7d6818bb6ca82ba5b769eeffd8f305) extracted the test manager
to a new class. In order to limit the surface area of the change
existing methods name were left unchanged.

This change updates those method names to make them explicitly
public so future test developers recognize their availability.

Change-Id: I3f3492dbe122797d9683e84373830e820cd8c038
Merge "Make SwiftScenarioTest methods public"