depends didn't have target-specific overrides for _build_env
so ANDROID_NDK_HOME wasn't being set at build time.
This fix supersedes the manual edit of Configuration/15-android.conf.
Resolves#8095
Depends cross compiles project dependencies for linux, mac and windows and multiple architectures.
Depends is original work by Cory Fields and used in bitcoin and a wide range of bitcoin related projects.
Howard Chu
selsta
kozyilmaz
TheCharlatan