Also create new subpackage frida-dev with libraries and include files.
Frida should be built with ndk r22 but I have now patched it to use
r21 since we have not switched to r22 yet. Using a lower version
might break stuff, but frida-python is already broken anyways since it
relies on python3.8 so building with r21 does not make the current
situation worse.
Updating it now so that the version in the Bintray repos will not be
left in guaranteed broken state.
The CC and CXX environmental variables cannot be set to the cross
compiler, meson expects them to point to the native compiler and the
build fails when meson tries to execute binaries compiled with CC and
CXX, as part of the configure tests (sanitycheckc.exe fails to
run). Unsetting CC and CXX means that clang and clang++ from the frida
sdk is used instead of the ones from the android-ndk. This is probably
fine for our purposes (and could otherwise be changed by patching
releng/setup-env.sh).
