Support IP Address verification on Android

[complexspaces]

After the webpki upgrade inside of #14, we now have the ability to verify IP address subject names on Android (Linux and WASM got this for free), once we upgraded.

The relevant ares are:

rustls-platform-verifier/src/verification/android.rs

Lines 283 to 286 in c18e462

	let server = match server_name {
	rustls::ServerName::DnsName(name) => name.as_ref(),
	_ => return Err(unsupported_server_name()),
	};

rustls-platform-verifier/src/verification/android.rs

Lines 191 to 197 in c18e462

	// If everything else was OK, check the hostname.
	let cert = webpki::EndEntityCert::try_from(end_entity.as_ref())
	.map_err(pki_name_error)?;
	let name = webpki::SubjectNameRef::DnsName(
	// This unwrap can't fail since it was already validated before.
	webpki::DnsNameRef::try_from_ascii_str(server_name).unwrap(),
	);

We should also make sure to enable the IP address portion of the mock test suite for Android at the same time to confirm the system supports the behavior.