`copyToInternalDirPath` should return same url path

[yjp018]

Describe the bug
当导入多次同一个文件名的m3u文件时，旧的会一直保留在同一个播放列表

Expected behavior
希望能导入新文件时自动覆盖旧列表而不是同时保留

Smartphone (please complete the following information):

• Device: REDMI K40
• OS: [MIUI14. Android 11]
• Version [1.15.0]

[oxyroid]

https://github.com/oxyroid/M3UAndroid/blob/master/data/src/main/java/com/m3u/data/repository/playlist/PlaylistRepositoryImpl.kt#L601-L619

[oxyroid]

当前确定问题代码了，将会在未来修复