Native v8.2.1

This release adds media and file sharing capabilites to thread replies. It also addresses a few issues with background sync and makes some cosmetic fixes.

• Adds the ability to attach or record videos to replies (threads) in Chat channels and DMs
• Adds support for recording and playing back voice messages with transcriptions in threads
• Adds support for uploading arbitrary file types in threads
• Fixes an issue where background sync would sometimes fail to launch
• Improves the empty channel message for new channels and groups