Increase code coverage in botbuilder library - ChannelServiceRoutes c…

…lass (#2540)

* add tests for channelServiceRoutes

* fix typos

* Repaced setTimeout with Promise

* Improve error catching

Co-authored-by: Santiago Grangetto <[email protected]>
Co-authored-by: Joel Mut <[email protected]>
Co-authored-by: Cecilia Avila <[email protected]>