Cannot use SendSMS Workflow Action with Group in 7.x

[cabal95]

Prerequisites

• Put an X between the brackets on this line if you have done all of the following:
  • Can you reproduce the problem on a fresh install or the demo site?
  • Did you include your Rock version number and client culture setting?
  • Did you perform a cursory search to see if your bug or enhancement is already reported?

Description

It looks like 7.0 refactored the way the SendSMS handles the merge fields when working with a group. From what I can tell it passes the mergeFields variable to the RecipientData object, which maintains a reference to it instead of a copy of it. Then the SendSMS action adds a "Person" object to the MergeFields. When using a Group, this causes a "An item with the same key has already been added." error because the dictionary already has a "Person" object from the previous loop through the group members.

Reported on Slack, confirmed on prealpha.

Steps to Reproduce

1. Create Workflow with SendSMS action.
2. Set the target to be a group with 2 or more people in it.
3. Run the workflow.

Expected behavior:

Message should be sent to multiple people.

Actual behavior:

Workflow throws an error.

Versions

• Rock Version: 7.0, 8.0
• Client Culture Setting: en-US