Image loading is very slow

**Describe the bug**
Large images are too slow to load.

**To Reproduce**
Send/receive a large image (my problem-image was 12 MB with a res of 6000x8000). The preview will show fine relatively quickly in the timeline. Clicking on the image to view it fullscreen will take a *very* long time. It's actually fast to just save the image to local storage and open it in the native gallery app.

**Expected behavior**
I expect element on android to display images fullscreen without delay when I click them and they're already previewed in the timeline.

**Smartphone (please complete the following information):**
- Device: Moto G4 Plus
- OS: LineageOS

**Additional context**
- From fdroid, element is version 1.0.12
- Homeserver: matrix.org

IIRC the local gallery app will (by default) not show large/high-res images at full quality, to prevent this exact scenario (high res images taking forever to display at fullscreen). Element could do something similar. It doesn't make sense to try to display insane resolutions/qualities at 100% quality imo.