Fix Reproducible bilds

[sschueller]

This is not very important as this app doesn't really handle much sensitive information at time but it would be nice for this to work.

It may be easier to start over doing it this way: https://core.telegram.org/reproducible-builds#reproducible-builds-for-android

Current docs: https://github.com/sschueller/peertube-android/blob/develop/REPRODUCIBLE_BUILDS.md

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