Timeline bar chart not loading on Android

- [x] I am on the [latest](https://github.com/ActivityWatch/activitywatch/releases/latest) ActivityWatch version.
- [x] I have searched the issues of this repo and believe that this is not a duplicate.

- **OS name and version**: Android 10
- **ActivityWatch version**: v0.12.1

## Describe the bug
timeline barchart show loading message but never load

## To Reproduce

Steps to reproduce the behavior, for example:
1. Go to Activity
2. Click on add visualization
3. Add timeline(barchart)
4. See error

## Expected behavior
show barchart

## Documentation

## Additional context