oeqa/ethernet_ip_connman : add test for network connections

This test mimic the ethernet_static_ip_set_in_connman and ethernet_get_IP_in_connman_via_DHCP test case from oeqa/manual/bsp-hw.json.
The ethernet_static_ip_set_in_connman and ethernet_get_IP_in_connman_via_DHCP manual test case should be remove from oeqa/manual/bsp-hw.json if this patch get merged.

Signed-off-by: Teoh Jay Shen <jay.shen.teoh@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>