Build is not reproducible (diffs in classes2.dex & png files)

[emanuelb]

Building last commit with: ./gradlew assembleRelease; ./gradlew clean; ./gradlew assembleRelease or by building container: podman build --rm -t bitstash_build_apk -f Containerfile.alpine

Containerfile.alpine:

FROM frolvlad/alpine-glibc

RUN set -ex; \
    apk update; \
    apk add --no-cache \
        openjdk8; \
    adduser -D appuser;

USER appuser

ENV ANDROID_SDK_ROOT="/home/appuser/app/sdk" \
    ANDROID_HOME="/home/appuser/app/sdk"

RUN set -ex; \
    mkdir -p "/home/appuser/app/sdk/licenses" "/home/appuser/app/bitstash/"; \
    printf "\n24333f8a63b6825ea9c5514f83c2829b004d1fee" > "/home/appuser/app/sdk/licenses/android-sdk-license"; \
    cd /home/appuser/app/bitstash/; \
    wget https://github.com/bitstashco/BitStash-Android-Wallet/archive/refs/heads/master.zip; \
    unzip master.zip; \
    rm master.zip;
    
WORKDIR /home/appuser/app/bitstash/BitStash-Android-Wallet-master/
RUN set -ex; \
    (./gradlew assembleRelease || ./gradlew clean); \
    ./gradlew assembleRelease

Comparing the generated apk to one from google-play, result in difference in many files.

1. many diffs in .png files, probably cause build process optimize the PNG, which should be avoided, see disabling cruncherEnabled at: https://f-droid.org/en/docs/Reproducible_Builds/#png-crushcrunch or maybe other setting like vectorDrawables.useSupportLibrary = true, etc..
2. classes2.dex files are different