Summary:
`RCTImageView` is now a subclass of `RCTView` and includes `UIImageView` as it's subview.
This enables the use of `borderRadius`, `borderWidth`, `borderColor` properties and all of their derivatives.
Possible problem:
Now `RCTImageView` is backed by two views (`RCTView` + `UIImageView`), not a single one. That's 4 `CALayers`. Possible workaround would be to insert the image directly into `self.layer.contents`.
Reviewed By: RSNara
Differential Revision: D14875673
fbshipit-source-id: 594b2cd1ddffc6627566e07983c6d8f0b37dc2bb