Android10Resolver: add test

package at.bitfire.davdroid

import android.os.Build

import androidx.test.filters.SdkSuppress

import org.junit.Assert.assertEquals

import org.junit.Test

import org.xbill.DNS.ARecord

import org.xbill.DNS.Lookup

import org.xbill.DNS.Type

import java.net.InetAddress

class Android10ResolverTest {

    val FQDN_DAVX5 = "www.google.com"

    @Test

    @SdkSuppress(minSdkVersion = Build.VERSION_CODES.O)

    fun testResolve() {

        val www = InetAddress.getByName(FQDN_DAVX5)

        val srvLookup = Lookup(FQDN_DAVX5, Type.A)

        srvLookup.setResolver(Android10Resolver)

        val resultGeneric = srvLookup.run()

        assertEquals(1, resultGeneric.size)

        val result = resultGeneric.first() as ARecord

        assertEquals(www, result.address)

    }

}

 No newline at end of file

        future.await()

    }

    override fun sendAsync(query: Message, listener: ResolverListener): Any {

        val id = Any()

        resolver.rawQuery(null, query.toWire(), DnsResolver.FLAG_EMPTY, executor, null, object: DnsResolver.Callback<ByteArray> {

            override fun onAnswer(rawAnswer: ByteArray, rcode: Int) {

                listener.receiveMessage(id, Message(rawAnswer))

            }

            override fun onError(error: DnsResolver.DnsException) {

                listener.handleException(id, error)

            }

        })

        return id

    }

    override fun sendAsync(query: Message, listener: ResolverListener) =

        // currently not used by dnsjava, so no need to implement it

        throw NotImplementedError()

    override fun setPort(port: Int) {