[native] Fixes for handling encrypted media messages

Summary:
Various places required adding a check for encrypted media types in order to display and handle messages correctly.

Depends on D7226
Depends on D7227

Test Plan:
When received messages containing encrypted_photo or encrypted_video from keyserver:

• Ensured play button is displayed for encrypted video thumbnails
• Ensured video modal is open when clicking encrypted video
• Ensured media gallery displays encrypted media and they are filterable (photo/video)

Reviewers: atul, rohan, marcin

Reviewed By: atul

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D7228