Check NRV visibility before modifying constraints

[ScoutHarris]

Fixes #11387

According to the Fabric logs, this crash seems to happen when searching the Free Photo Library.

51 | 1556091505912 | 🔵 Tracked: stock_media_accessed
52 | 1556091512547 | 🔵 Tracked: stock_media_searched
53 | 1556091514021 | 🔵 Tracked: stock_media_searched
54 | 1556091515163 | 🔵 Tracked: stock_media_searched
55 | 1556091515401 | 🔵 Tracked: stock_media_searched
56 | 1556091520549 | 🔵 Tracked: stock_media_searched
57 | 1556091525780 | 🔵 Tracked: stock_media_searched

I was not able to reproduce the crash, but this sort of crash typically happens when the NRV isn't actually visible so it fails when setting the constraints according to the view. So I added a check to ensure the NRV is visible before setting the constraints. 🤞 this fixes it.

To test:

• Access the Free Photo Library.
• Perform searches that have no results.
• Verify it doesn't crash.

Update release notes:

• If there are user facing changes, I have added an item to RELEASE-NOTES.txt.

[danielebogo]

Thanks @ScoutHarris for adding this! The code looks good and I never got a crash while I was testing it!