Sending image hangs indefinitely

### Steps to reproduce

1. Open an existing 1:1 room with another user on the same homeserver.
2. Tap the "+" icon in the bottom-left corner.
3. Tap "Photo & Video Library".
4. Tap an image.
5. Tap the send button.

### Outcome

#### What did you expect?

The image should be sent to the other user.

#### What happened instead?

The "Sending..." dialog and animated spinner are displayed indefinitely (or at least for the two minutes that I've waited). After I click "Cancel", the send button no longer responds to taps. I get the same results after closing the image activity and trying again.


This happens when sending to different users on my homeserver. I'm able to send image attachments to the same users without any problems from Element Web v1.11.99.

It doesn't appear to be connectivity-related; I see the same behavior on cellular and wifi. I believe that this worked for me in the past.

### Your phone model

Pixel 7a

### Operating system version

Android 15

### Application version and app store

Element X 25.04.3 (Play Store)

### Homeserver

Synapse 1.128.0

### Will you send logs?

Yes

### Are you willing to provide a PR?

No