try this way (My Android device worked)

DHCP IP

    ifconfig eth0 dhcp

OR

    setprop dhcp.eth0


OR

    dhcpcd -k eth0
    dhcpcd -n eth0

OR 

    netcfg eth0 dhcp
OR

    getprop dhcp.eth0

and 
Static IP

    ifconfig eth0 192.168.70.145 netmask 255.255.255.0 up
    route add default gw 192.168.70.254 dev eth0
or 

    su -c ifconfig eth0 192.168.70.145 netmask 255.255.255.0 up
    route add default gw 192.168.70.254 dev eth0

Enable Ethernet

    ifconfig eth0 up
Disable Ethernet

    ifconfig eth0 down

and check wlan0 static or dynamic?
my device when wlan0 is static force once set eth0 static and after set static change to dynamic

check the device ip:

    ip addr

********** try this android 5.1 ****************** eth0 dhcp

    ifconfig eth0 down
    ifconfig eth0 up
    dhcpcd -k eth0
    dhcpcd -n eth0
    netcfg eth0 dhcp