Fix test timing to wait for view to be rendered before running expectations

[jonsnyder]

Description

The configuration spec "initializes form fields with full settings", was consistently failing on my machine. I found that the problem was that the test runner was not waiting long enough after initializing the extension view controller before running expectations. I changed it so that it now waits for the rendered event before continuing. This caused a problem because when an error is thrown, the rendered event isn't triggered. I added a trigger for this in the error boundary. This uncovered a problem with one of the update variable tests. It was trying to verify that an error was not shown, but because it was checking too early it was succeeding even though the error would show if it waited until the view was rendered. I fixed this by updating a test to pull down mocked versions of the schema.

Related Issue

Motivation and Context

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Improvement (non-breaking change which does not add functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I have signed the Adobe Open Source CLA or I'm an Adobe employee.
• I have made any necessary test changes and all tests pass.
• I have run the Sandbox successfully.
• I've updated the schema in extension.json or no changes are necessary.
• My change requires a change to the documentation.