Add minimum GPS accuracy preference for logging

[Andyporras]

Introduces a new user preference to set the minimum required GPS accuracy before starting to record track points. Updates the GPSLogger service to wait until the specified accuracy is achieved, and adds relevant UI strings and preference entry.

📝 Feat: Settings: minimum GPS accuracy to start recording track

🛠️ Issue

• Closes Settings: minimum GPS accuracy to start recording track #444

🛠️ Related issues (if applicable)

• N/A

📖 Description

This PR introduces a new user preference to set the minimum required GPS accuracy before starting to record track points.

Changes:

• Preferences UI: Added a new EditTextPreference in the GPS Settings menu (prefs_gps_min_accuracy) allowing users to input a value in meters (e.g., 10). Default is 0 (disabled).

• Logic Implementation: Updated GPSLogger.java to read this preference.

  • Added a "latch" mechanism (isAccuracySatisfied).
  • The service now ignores incoming location updates until one arrives with an accuracy better than or equal to the configured value.
  • Once the accuracy is met, recording starts normally for all subsequent points.

• Strings: Added necessary string resources for the new setting.

Rationale: This prevents the recording of widely inaccurate points (jumping) that often occur immediately after starting the GPS, significantly improving the quality of the track's start, especially for vertical distance computation.

🖼️ Screenshots (if applicable)

✅ Pull Request Checklist

• The PR is proposed to the DEVELOP branch.
• The changes have been tested on the target Android API and minimum Android API.
• Automated tests have been added (if applicable).
• The feature is well documented.
• There is a reference to the original ISSUE and related work.

📝 Additional Notes

The logic ensures that we only wait once at the beginning. If the GPS accuracy degrades later (e.g., entering a tunnel), the recording continues uninterrupted to avoid gaps in the track, satisfying the requirement to "wait before starting".

[jamescr]

Move preference keys and default values to OSMTracker. Preferences class. Check this commit for an example.

Min accuracy preference is numeric; consider using the setupEditTextNum() method from Preference Activity to force numeric inputs and add an option to reset to default value.

[Andyporras]

Thanks @jamescr for the review. I've just refactored the code to move the constants to OSMTracker.Preferences and implemented setupEditTextNum() for the input field validation. Ready for another look!

[jamescr]

Andy, I reviewed the PR again, this time with more detail. You can see my suggestions in this branch.

In general, the code was reordered, and some variables were renamed to keep consistency with the style of the files and project. I add a new string in strings-preferences.xml to avoid reusing a string with another purpose.

Using 0 as the default value for the GPS logging accuracy is a bad practice because it could be interpreted by a user as the highest precision (0 m precision). One possible way to manage this could be with 2 preferences, one that enabled the GPS logging accuracy value and another that set the value (like the case of the background map prefs). But, we still have to consider a default value for the pref. A low value (let's say 2m) could take longer to be acquired, and the user could have the perception the app stops working. So a UI indicator will be needed to avoid the wrong perception.

My point of view is that it probably would be better to have accuracy ranges and not a value. I mean, with this, something like High Precision (1m-10m), Standard (10m-30m) and Low Precision (30m+). And the default could be Standard.

I open a PR to your repo just in case. The code in the branch is rebased. In Preferences.java I change a typo and delete an unused lib that was not part of your code.