Summary:
Changes the `onLoad` and `onError` events on `Image` to be consistent with each other and with the `ImageSource` type.
Changelog:
[Android][Breaking] - On `Image`, `onLoad` and `onError` event objects will no longer have an extra `uri` property.
[Android][Breaking] - On `Image`, `onLoad` event objects' `source.url` is now renamed to `source.uri`.
[iOS][Breaking] - On `Image`, `onLoad` event objects' `source.url` is now renamed to `source.uri`.
Reviewed By: mdvacca
Differential Revision: D22023565
fbshipit-source-id: 5ea7904c697f87e01118bdb81ed50ab0a5aecdce
Tim Yung
74ab8f6e5a