GPX export assigns duplicate names to the file with dates

[Andyporras]

Description:
When exporting as a GPX file, if a date-based name is assigned, the exported file duplicates the date in its name. If a custom name is assigned, the system appends the creation date to the end of the custom name. This affects only the GPX file, as the folder is generated correctly.

Steps to reproduce the problem:

1. Start OSMTracker on a device.
2. Record a route and end the recording.

Export as a GPX file.

Case 1: Export without assigning a name (let it be generated with date).
Case 2: Export by assigning a custom name.
Check the name of the exported file.

Expected behavior:

In case 1, the file should be generated with the exact date as name (unique format, no duplicates).
In case 2, the file should keep the custom name without adding the creation date.

Case 1: The GPX file contains the duplicate date in its name.
Case 2: The GPX file appends the creation date to the custom name.

Additional notes:
The observed behavior occurs only with GPX file names, while the associated folders are generated correctly. This could be a problem in the naming logic in the export function.

[Andyporras]

note: this only occurs when the “FILENAME_NAME_DATE” preference is selected.

[Andyporras]

this has already been resolved in the pr:

• Customized export label for file sharing (#333, #470) #483