Android: Remove libgnustl_shared.so copy hack.

It's not needed, and when $outpath/lib doesn't already exist
(when shadow-building for example), $outpath/lib ends up being
a copy of libgnustl_shared.so, when it really must be a folder.

Change-Id: Iaf3af6f4183090137043549cb8d9899c2bc92f24
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@digia.com>