Reproducible builds

Continuing from https://gitlab.com/IzzyOnDroid/repo/-/issues/160 as discussed:

We still cannot reproduce the builds – neither using JDK 17 nor 21. Here are the diffs: [diff_jdk17.zip](https://github.com/user-attachments/files/20068484/diff_jdk17.zip) & [diff_jdk21.zip](https://github.com/user-attachments/files/20068483/diff_jdk21.zip)

Differences are in `classes.dex`. Using JDK 21, the diff seems to indicate our build has additional annotations – which usually means "the other APK" was built with JDK 17 (it's quite typical that 21 has additional annotations). However, using JDK 17 we have a lot of "identical differences" in `com/cylonid/nativealpha/__WebViewActivity`, mostly addresses not matching. This could mean a "flaky" (aka "non-deterministic) build – or a "dirty build" on your end (i.e. the APK not being built from a clean tree: local changes or, more likely from how the diff looks, artifacts remaining from a previous build).

So first questions would be:

* which JDK are you using?
* did you run `clean` before you built your APK?

We tried last with v1.5.1, and that's where above diffs come from.