ci/android: Switch to using the Android NDK.

ci/android: Switch to using the Android NDK.

To support Android drivers, we're going to want to be tracking that Mesa's
build succeeds on a real android toolchain.  This still uses the android
stubs since these libs aren't in the NDK.

Note that I had to drop the Intel and AMD drivers currently: we don't have
LLVM cross-compiled for Android in this container, and I'm honestly hoping
ACO saves us from that.  Intel has dependencies on libexpat, which AOSP
really doesn't want to bring in, and it looks to me like those dependencies
could be optional.

Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6700>