Summary:
Resolves #7081 by allowing iCloud to download photos not stored on the device.

**Test plan (required)**

1. Verified existing photos stored on the device still display.
2. Deleted my iCloud photo library from my phone and verified the image downloads and displays.
Closes https://github.com/facebook/react-native/pull/9530

Differential Revision: D3838470

Pulled By: mkonicek

fbshipit-source-id: 810830a4246714b6e166e4411f3fa848b1f1b71c