install_base.sh: Fix default value of devlib parameters

FIX

Don't call devlib's setup_host.sh script if install_base.sh is executed
with --install-all argument or a devlib specific parameter is provided
to install_base.sh.

Fixes: 8bbce4c2 ("install_base.sh: Offload Android SDK/tools installation to devlib")
Signed-off-by: Metin Kaya <metin.kaya@arm.com>