Change validation for file input on change event.

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: master
• Fix Version/s: 2.0.x, master, master-deprecated, 3.0.x, 2.0.0.68-deprecated, 3.1.x
• Component/s: Form Validator
• Labels: None
• Git Pull Request: https://github.com/jonmak08/alloy-ui/pull/326

Currently, file input validation is triggered by blur event.

However, this is not user-friendly,

When click on the choose button, a pop-up appear and the validation is triggered. But the end user has not started to upload a file.

Changing to change event will validate the file input only when a file is uploaded.