Merge branch 'develop' into pre-alpha-release

# Conflicts:
#	Rock/Communication/Chat/ChatHelper.cs

- Improved the "Send Fallback Chat Notification" Automation Event's a…

…bility to accurately determine which Chat members should receive fallback notifications.

(cherry picked from commit 09ccab9)

- Updated build version to 17.2.4

- Updated build version to 17.2.4

- Updated build version to 17.2.3

- Updated build version to 17.2.2

+ (Communication) Fixed an issue where if a recipient was merged befo…

…re a scheduled Communication was sent, the updated recipient was removed at send time. The fix now ensures that valid recipients are retained even after a merge. (Fixes #6255)

- (Communication) Removed webhook-related properties from the Stream …

…chat AppSettingsRequest configuration object that are no longer allowed to be set via their REST API.

Merge branch 'develop' into pre-alpha-release

- Version update for 16.11 alpha packaging.