-specifically cl 9616691 9630939 9743710
-Fixes UEVR-1502 Hololens 2 - Remoting AR Session is not automatically stopped when vrpreview session ends.
-Ups remoting app version compatibility to 2.0.12.0
-fixes bugs with gestures
-fixes some threading problems
-implements device connected/disconnected hooks for remoting
#jira UEVR-1502
#rb Joe.Conley Jackson.Fields
#ROBOMERGE-OWNER: jeff.fisher
#ROBOMERGE-AUTHOR: jeff.fisher
#ROBOMERGE-SOURCE: CL 9843215 in //UE4/Release-4.24/...
#ROBOMERGE-BOT: RELEASE (Release-4.24 -> Main) (v548-9842178)
[CL 9843351 by jeff fisher in Main branch]