Prevent video stop in MediaPageViewController when new attachment arrives.

[alex1704]

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• [x] I have read the README and CONTRIBUTING documents
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Contributor checklist

• [x] My commits are rebased on the latest main branch
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• [x] My contribution is fully baked and is ready to be merged as is
• [x] I have tested my contribution on these devices:

• iPhone 7, iOS 15.7.9

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Description

When user opens video attachment, MediaPageViewController presents it and play it. If in this moment user receives new attachment - audio or video then video stops playing. Solution is to reload attachment only if it is different then current one.

Steps to reproduce: Assuming that phone1 received video attachment (say 20 seconds long) at some point

1. on phone1 open mentioned video attachment
2. on phone2 send to phone1 photo or audio message
3. video on phone1 stops playing