Errors from rtmedia during document upload and edit

[maharrshi]

Describe the bug unable to edit a document

To Reproduce Steps to reproduce the behavior:

1. Go to Media-> Documents
2. Upload a new document of type: pdf
3. observe the errors in the dev console: Attempt to read property "media_author" on null when start upload is pressed.
4. Observe the document count to be not updated when the new document is uploaded.
5. Edit the document
6. See errors and warnings related to rtmedia plugin from the query monitor while saving the update.

Expected behavior No error messages to be shown

Screenshots or Visual

https://github.com/user-attachments/assets/d3132a29-42eb-4307-96fc-f4ec990c1678

Tested with : rtmedia: pre-release branch rtmedia-pro: pre-release branch