Thanks, got it running. However, I came across the following challenge:
The plugin supports to upload multiple apks, selected by a pattern. Usually each of these apks hast its own mapping-file. With just an additional pattern for the mapping-files the plugin couldn't know, which mapping benlongs to an apk.
A very simple solution could be to allow upload of mappings only in case of a single apk. This would solve my current usecase, but would not work for those having a complex setup with multiple apks.
As a better alternative the pattern for the mappings could be handled relative to the directory of each apk-file. This would fit for my usecase with only one apk, but also multi-module gradle-projects with severeal apk-modules, where each module produces a directory structure like this:
A valid mapping-file-pattern could then be "../mapping/*/mapping.txt". As far as I can see, this could handle both, projects with a single and multiple apks. Or are there any other project-setups, that you had in mind when you implemented support for multiple apks?