Fix last remaining test on Android

Motivation

Get all tests passing on Android AArch64

Modifications

- Use the right localhost alias for BootstrapTest/testClientBindWorksOnSocketsBoundToEitherIPv4OrIPv6Only

Result

All tests pass natively on Android AArch64

Tests/NIOPosixTests/BootstrapTest.swift

@@ -644,10 +644,15 @@ class BootstrapTest: XCTestCase {
 
             var maybeChannel1: Channel? = nil
             // Try 2: Connect to "localhost", this will do Happy Eyeballs.
+            #if canImport(Darwin)
+            let localhost = "localhost"
+            #else
+            let localhost = isIPv4 ? "localhost" : "ip6-localhost"
+            #endif
             XCTAssertNoThrow(maybeChannel1 = try ClientBootstrap(group: self.group)
                                 .channelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
                                 .bind(to: clientLocalAddressWholeInterface)
-                                .connect(host: "localhost", port: server1LocalAddress.port!)
+                                .connect(host: localhost, port: server1LocalAddress.port!)
                                 .wait())
             guard let myChannel1 = maybeChannel1, let myChannel1Address = myChannel1.localAddress else {
                 XCTFail("can't connect channel 1")