p4a ref: electrum_20240930_android_16kb_page_alignment
Dockerfile: obtain 16kb aligned NDK r23 from google CI (dl-ndk-ci.sh)
barcode, zxing-cpp: add 16kb align patch
build_tools_util.sh: add function to apply a patch
Adds a script `make_barcode_scanner.sh` which builds the
`BarcodeScannerView` library and its dependencies, `zxing-cpp` and
`CameraView` from source. Builds `zxing-cpp` architecture dependent
reducing the final apk size.
