Reproducible Builds

Just a note: please always tag the commit you've built from (or build from the commit you've tagged). For the current release, RB initially failed, because the APK was built from the commit _following_ the tag. Luckily, it was from a clean tree, so we were able to manually adjust and make it succeed 😉 Recommended reading: [RB Hints for Developers](https://izzyondroid.org/docs/reproducibleBuilds/RBDevHints/), especially the "first basic rule" (about 80% of failed RBs were caused by violation of that rule, like yours just now 🙈). Thanks a lot! 🤗