All you need to cross-compile aria2 for Android.
Clone the repository with submodules (--recurse-submodules), install the Android NDK r23, set the ANDROID_NDK_HOME
env variable and run ./build_all.sh.
This will compile aria2 for armeavi-v7a, arm64-v8a, x86 and x86_64. The binaries can be found inside the bin
folder.