Change tauri identifier when building with "system_settings" feature

To avoid having conflicting android package names for the "system" build and the "user" build, Volla requested different android package names.

AC:
- add a `tauri.system.conf.json` with the new identifier
- add a `tauri.user.conf.json` with the new identifier (optional - this could stay the same)
- modfiy the ci workflow `release-apps.yml`: for all commands that run `pnpm run build:android-service-runtime` add the additional flag ` -- config tauri.${{ matrix.label }}.conf.json`

Start with the Android build configuration and the release-apps.yml workflow. Review how build:android-service-runtime is invoked for each matrix label and verify the existing identifier settings. Done means system and user builds use the intended package identifiers and every relevant workflow command selects the matching configuration.

Written by the indexing model from the issue text.