[Success] for Android + StrongSwan VPN Client Local DNS

root@OpenWrt:/etc# cat /etc/strongswan.conf
# strongswan.conf - strongSwan configuration file

charon {

  dns1 = 192.168.1.1                #(OpenWrt Router's LAN IP Address)

  threads = 16

  plugins {
        attr {
                dns = 192.168.1.1  # (OpenWrt Router's LAN IP Address)
        }

    dhcp {
        server = 192.168.1.1
    }
  }

}

pluto {

}

libstrongswan {

  #  set to no, the DH exponent size is optimized
  #  dh_exponent_ansi_x9_42 = no
        crypto_test {
                       on_add = yes
        }
}