fix: initial size of bottom sheet

[vitoksmile]

Description

BottomSheet on timeline is overlaping selected photos in selection mode (see attached video).

In this PR I set the initial size of BottomSheet as minimim size, so it does not take half of the screen.

How Has This Been Tested?

1. Open timeline
2. Long press to select a photo

Actual result: BottomSheet is overlaping is photo is on first half of the screen (on top).
Expected result: Selected photo is still visible until users manually expand the BottomSheet.

Screenshots

The actual behaviour:

timeline_actual.mp4

Fixed behaviour:

timeline_fixed.mp4

Checklist:

• I have performed a self-review of my own code
• I have made corresponding changes to the documentation if applicable
• I have no unrelated changes in the PR.
• I have confirmed that any new dependencies are strictly necessary.
• I have written tests for new code (if applicable)
• I have followed naming conventions/patterns in the surrounding code
• All code in src/services/ uses repositories implementations for database calls, filesystem operations, etc.
• All code in src/repositories/ is pretty basic/simple and does not have any immich specific logic (that belongs in src/services/)

Please describe to which degree, if any, an LLM was used in creating this pull request.

No LLM

[vitoksmile]

@danieldietzler could you update labels? we only need changelog:bugfix and mobile

[alextran1502]

Thanks <3

[vitoksmile]

@alextran1502 could you update labels for this PR to remove "documentation" and include "mobile" instead