Fixes media upload to channels

[noelcarcasesLYN]

Summary

Fix media upload for channels by correcting two issues in processMediaData:

• Use mediaInfo.mimetype instead of file.type when creating opaque data, ensuring the correct MIME type is passed
• Pass getRandomFilehash as a function reference instead of invoking it immediately with getRandomFilehash()

Changes

Utils.js:449: Fixed MIME type parameter for OpaqueData.createFromData

- const opaqueData = await window.Store.OpaqueData.createFromData(file, file.type);
+ const opaqueData = await window.Store.OpaqueData.createFromData(file, mediaInfo.mimetype);
Utils.js:503: Fixed calculateToken to pass function reference
- ...(sendToChannel ? { calculateToken: window.Store.SendChannelMessage.getRandomFilehash() } : {})
+ ...(sendToChannel ? { calculateToken: window.Store.SendChannelMessage.getRandomFilehash } : {})

[tlgsn]

Yes, it works well. Thank you.

[tahafatih]

Its worked. Thank you.

[danpasecinic]

Can confirm, works like a charm!

[owen800q]

@tahafatih @tlgsn @danpasecinic Can you help merge this PR?
thanks

[danpasecinic]

@owen800q we can't merge PR without at least 2 reviews by reviewers with write access to repository.