Summary:
Second attempt at adding border properties to `RCTImageView`.
Previous attempt can be found at D14875673 which was reverted.
1. `UIImageView` is no longer laid out in in `layoutSubviews`.
2. `updateWithImage` was not being called, I instead of calling `self.image = image` I was calling `_imageView.image = image` directly which skips calling `updateWithImage`. This meant that image's rendering mode was not changed to `template`.
Reviewed By: shergin
Differential Revision: D14934103
fbshipit-source-id: b74c692f9f8ad520ef1f9c70ec4b4aa68b868cd4
51990014eb