[Designer] Data binding button produces invalid binding for arrays

[soloughlin]

Problem Description

Clicking the ... or Bind... data binding button and selecting a property which is an array, or is contained in an array produces data binding strings in the form ${$root['propertyName[0]'}, which are not valid.

Card JSON

{
    "type": "AdaptiveCard",
    "$schema": "http://adaptivecards.io/schemas/adaptive-card.json",
    "version": "1.5",
    "body": [
        {
            "type": "TextBlock",
            "text": "${$root['employees[0]']['name']}",
            "wrap": true
        }
    ],
    "data": {
        "employees": [
            {
                "name": "Gabriela Leticia"
            },
            {
                "name": "Natalia Tercera"
            },
            {
                "name": "Waleska Cristobal"
            }
        ]
    }
}

Screenshot