Make help panel fallback to help desk if no mentor is available

This moves GEHelpPanelAskMentor to JS config variable,
because it is not possible to get current user within ResourceLoaderContext.

Bug: T275908
Bug: T273782
Change-Id: I44fc0cdedb9fe0d900245b3014d5ac61df85e08f
(cherry picked from commit ab1feb53cc5945705f9678d5d2b97be00977a617)
2 files changed