Volume converter uses an inaccurate factor for US fluid ounces

[fubai578]

Checklist

• I can reproduce the bug with the latest version given here.
• I made sure that there are no existing issues - open or closed - to which I could contribute my information.
• I made sure that there are no existing discussions - open or closed - to which I could contribute my information.
• I have read the FAQs inside the app (Menu -> About -> FAQs) and my problem isn't listed.
• I have taken the time to fill in all the required details. I understand that the bug report will be dismissed otherwise.
• This issue contains only one bug.
• I have read and understood the contribution guidelines.

Affected app version

### Affected Android/Custom ROM version

Android 14 (API 34)

### Affected device model

MuMu Android Emulator (900 x 1600)

### How did you install the app?

F-Droid / IzzyOnDroid

### Steps to reproduce the bug

1. Open the unit converter in Fossify Calculator and select **Volume**.
2. Set the input unit to `Fluid Ounce (US)` and the output unit to `Liter`.
3. Enter `100` and read the result.

### Expected behavior

The result should be approximately `2.95735 L`.

### Actual behavior

The converter shows exactly `3 L`, which matches an approximate `0.03 L per fl oz` factor rather than the real 0.0295735 L.

### Screenshots/Screen recordings

<img width="900" height="1600" alt="Image" src="https://github.com/user-attachments/assets/16fe49f2-9919-49c7-8e55-d9419f4bf0b7" />

### Additional information

- Package: `org.fossify.math`
- Tested version: 1.4.0 (version code 10)
- Environment: Android 14 (API 34), MuMu Android Emulator (900 x 1600)

For cooking-sized amounts the rounding error is small, but for larger values the result drifts visibly away from the correct conversion.

[naveensingh]

@fubai578, please avoid mass-filing issues and fix the formatting in your existing reports.