1) If you have no router, you have only a single IP address available on your network. That means that you can have only 1 device running on it. (A switch connected to a non-routing modem does not a network make.) If you connect 2 TCP-IP devices to a "network" wiyh a single IP address (IOW, the cable coming into your house from the street) without a router, you won't have 2 devices connected to the internet, you'll have a mess. And if you assign them some arbitrary static IP address, it won't work,
(An IP address is like your house address. For mail to get to your house, it has to be addressed to the actual location of the actual house. If you live in New York and "assign" a California address to your house, you're not going to get any mail. It has to get "assigned" the "real" address it "lives" at.)
2) If you can't disable the DHCP client for the Ethernet adapter, you can't give it a static IP.
I can't even guess why you want to give the device a static IP address, but if you plug in the Ethernet cable (to both ends, the Android and the switch) does the Android get an IP address? If it does, then you do have a router in your network. Somewhere. In your house, in your provider's office - somewhere. Switches don't assign IP addresses.
The question is whether your "network" is coming from your router or your provider's router. If it's coming from your provider's router, then you get ONE IP address. That's it. You can assign all the static IP addresses you want to all the devices connected to your switch, but only the one with the IP address assigned by the provider's router is going to work.
If it's coming from your router then, whether you see a box that looks to you like a router or not, you have a router. (You may have a modem/router with a single Ethernet jack, which is connected to an external switch, to allow you to plug in multiple devices, but that's just putting the pieces in different boxes. What you're used to seeing is a modem connected to a "router" that has multiple Ethernet jacks (a switch) and an antenna (a wireless access point.) What you may be looking at is a modem/router connected to an external switch, and no wireless access point.
Bottom line. If you have no router between the street and your switch, you can run only 1 device. It has to get a dynamic IP address (unless you're buying a static IP address from your provider, which is a waste unless you're running a publicly-accessible server), because the provider assigns it an IP address every time you turn it on.
If you do have a router, you have no problem.
The only other possibility is that you want the Android to have a fixed IP address, so you can tell other devices what address it has (to send things to it, etc.) Easy solution - turn off all your other devices - computers, cellphones, etc. Plug the Android into the switch. Turn it on. It'll get an IP address - the first one your DHCP server leases. (And it always leases that one first.) If you have to switch things off, change wires, etc., do the same thing - the Android gets set up first, so it still gets that "first" IP address.
Hope I didn't give you more of a course in TCP-IP topology than you wanted.
