Move in required gettingstarted tour messages from GuidedTour

Add the gettingstarted messages and message documentation
that were removed from the GuidedTour extension in change I26ebc81f.

Remove unused messages

Bug: 53885
Change-Id: I694da22b1fb577db190beba5b4377caab42053fe
Merge "Move in required gettingstarted tour messages from GuidedTour"