MIME type autodetection instead of */*

#### Is your feature request related to a problem? Please describe.
I sent a spec-conforming file `application/geo+json` aka GeoJson. The displayed MIME type is
1. `application/geo+json` if the file was uploaded within Element Android, using the `+` button next to the message text box.
2. `*/*` if the file was shared ("Send to") from Ghost Commander to Element Android.

This is inconvenient, because clicking on the file in case 2 lists a lot of unrelated apps, but clicking in case 1 only lists apps that support `application/geo+json`.

#### Describe the solution you'd like.
Auto-detection for case 2, like in case 1.

#### Describe alternatives you've considered.

#### Additional context
Element 1.1.12 on Android 7