Optimise performance of Canvas widget on Android

### Describe the bug

Hello toga team,
I have an app with a canvas and I draw a little circle every time the user press the canvas.
But after a large number of circles, let say 100 or 200 circles, the app begins to lag and the new circles appear after a delay and the log say that some frames have been skipped.
I made the same kind of app with android studio and there is no slow down.
Do you have an idea of the problem ?
Than you.

### Steps to reproduce

Make a canvas.
Draw a circle at each on press event
Lags appear after many circles

### Expected behavior

No slow down on redraw

### Screenshots

_No response_

### Environment

- Operating System: android
- Python version: 3.12
- Software versions:
- Briefcase:
- Toga: 0.4.8
- ...

### Logs

```

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### Additional context

_No response_

Start by reproducing the lag on Android with a canvas that draws a circle on each press, using Toga 0.4.8 and Python 3.12. Investigate the Android Canvas widget's redraw behavior and frame-skipping logs; done means repeated presses remain responsive without delayed circles or skipped-frame warnings.

Written by the indexing model from the issue text.