Fix issue introduced by 17442b78a39fa24407e363a8c4b0025d3eed2c60

SFLPHONE_SRC was a duplicate of SFLPHONE_SRC_DIR

Choose correct libraries dependind on ARCH
Some dependencies adapt their lib name based on target arch.
This needed to be accounted for in Android.mk

Build is still mono-arch, you either build for arm XOR x86.

Refs: #57688

There was also a corner case with sflphone compilation
We checked if config.h existed to compile daemon
What happened: if configuration is successfull but right after compilation crashed,
next time compilation was skipped.
Hack was to delete config.h, but that was really unclear. We now run make every time.

Some values were empty, because IAX offers only a subset of SIP options

We do not use gnustl_shared/ssl/crypto anymore

Necessary for system with older autotools etc.

Built files are in sflphone/daemon/build-android-TUPLE/..., source files
are in sflphone/daemon/...

Does nothing for the time being

cherry-picked from vlc-android (with configure.sh fix):

commit 69e0648c6a331cb7171ff1841a870809685b8ddd
Author: Thomas Guillem <thomas.guillem@gmail.com>
Date:   Wed Oct 1 18:42:06 2014 +0200

    Build: add gnu-libstdc++ in EXTRA_LDFLAGS

    fix protobuf build.

pushd and popd are not available

Contrib path moved, and linking flags changed.

Refs #56330