Use a random service type for NsdManagerTest

When two devices connected to the same access point run the test
simultaneously, they may find each other when discovering for the same
service type, instead of finding themselves as expected by the test.

Similarly to the service name, use a random service type to avoid that.

Bug: 257459913
Bug: 248121960
Test: atest
Change-Id: I462841fb4331c6e441b74302f6463986472f1340
diff --git a/tests/cts/net/src/android/net/cts/NsdManagerTest.kt b/tests/cts/net/src/android/net/cts/NsdManagerTest.kt
index 357a8d1..2b5c305 100644
--- a/tests/cts/net/src/android/net/cts/NsdManagerTest.kt
+++ b/tests/cts/net/src/android/net/cts/NsdManagerTest.kt
@@ -88,7 +88,6 @@
 import kotlin.test.fail
 
 private const val TAG = "NsdManagerTest"
-private const val SERVICE_TYPE = "_nmt._tcp"
 private const val TIMEOUT_MS = 2000L
 private const val NO_CALLBACK_TIMEOUT_MS = 200L
 // Registration may take a long time if there are devices with the same hostname on the network,
@@ -112,6 +111,7 @@
 
     private val cm by lazy { context.getSystemService(ConnectivityManager::class.java) }
     private val serviceName = "NsdTest%09d".format(Random().nextInt(1_000_000_000))
+    private val serviceType = "_nmt%09d._tcp".format(Random().nextInt(1_000_000_000))
     private val handlerThread = HandlerThread(NsdManagerTest::class.java.simpleName)
 
     private lateinit var testNetwork1: TestTapNetwork
@@ -334,7 +334,7 @@
     @Test
     fun testNsdManager() {
         val si = NsdServiceInfo()
-        si.serviceType = SERVICE_TYPE
+        si.serviceType = serviceType
         si.serviceName = serviceName
         // Test binary data with various bytes
         val testByteArray = byteArrayOf(-128, 127, 2, 1, 0, 1, 2)
@@ -384,7 +384,7 @@
 
         val discoveryRecord = NsdDiscoveryRecord()
         // Test discovering without an Executor
-        nsdManager.discoverServices(SERVICE_TYPE, NsdManager.PROTOCOL_DNS_SD, discoveryRecord)
+        nsdManager.discoverServices(serviceType, NsdManager.PROTOCOL_DNS_SD, discoveryRecord)
 
         // Expect discovery started
         discoveryRecord.expectCallback<DiscoveryStarted>()
@@ -424,7 +424,7 @@
 
         // Register service again to see if NsdManager can discover it
         val si2 = NsdServiceInfo()
-        si2.serviceType = SERVICE_TYPE
+        si2.serviceType = serviceType
         si2.serviceName = serviceName
         si2.port = localPort
         val registrationRecord2 = NsdRegistrationRecord()
@@ -458,7 +458,7 @@
         assumeTrue(TestUtils.shouldTestTApis())
 
         val si = NsdServiceInfo()
-        si.serviceType = SERVICE_TYPE
+        si.serviceType = serviceType
         si.serviceName = this.serviceName
         si.port = 12345 // Test won't try to connect so port does not matter
 
@@ -467,7 +467,7 @@
 
         tryTest {
             val discoveryRecord = NsdDiscoveryRecord()
-            nsdShim.discoverServices(nsdManager, SERVICE_TYPE, NsdManager.PROTOCOL_DNS_SD,
+            nsdShim.discoverServices(nsdManager, serviceType, NsdManager.PROTOCOL_DNS_SD,
                     testNetwork1.network, Executor { it.run() }, discoveryRecord)
 
             val foundInfo = discoveryRecord.waitForServiceDiscovered(
@@ -492,7 +492,7 @@
         assumeTrue(TestUtils.shouldTestTApis())
 
         val si = NsdServiceInfo()
-        si.serviceType = SERVICE_TYPE
+        si.serviceType = serviceType
         si.serviceName = this.serviceName
         si.port = 12345 // Test won't try to connect so port does not matter
 
@@ -505,7 +505,7 @@
 
         tryTest {
             val specifier = TestNetworkSpecifier(testNetwork1.iface.interfaceName)
-            nsdShim.discoverServices(nsdManager, SERVICE_TYPE, NsdManager.PROTOCOL_DNS_SD,
+            nsdShim.discoverServices(nsdManager, serviceType, NsdManager.PROTOCOL_DNS_SD,
                     NetworkRequest.Builder()
                             .removeCapability(NET_CAPABILITY_TRUSTED)
                             .addTransportType(TRANSPORT_TEST)
@@ -514,7 +514,7 @@
                     executor, discoveryRecord)
 
             val discoveryStarted = discoveryRecord.expectCallback<DiscoveryStarted>()
-            assertEquals(SERVICE_TYPE, discoveryStarted.serviceType)
+            assertEquals(serviceType, discoveryStarted.serviceType)
 
             val serviceDiscovered = discoveryRecord.expectCallback<ServiceFound>()
             assertEquals(registeredInfo1.serviceName, serviceDiscovered.serviceInfo.serviceName)
@@ -560,7 +560,7 @@
         assumeTrue(TestUtils.shouldTestTApis())
 
         val si = NsdServiceInfo()
-        si.serviceType = SERVICE_TYPE
+        si.serviceType = serviceType
         si.serviceName = this.serviceName
         si.port = 12345 // Test won't try to connect so port does not matter
 
@@ -571,7 +571,7 @@
         val specifier = TestNetworkSpecifier(testNetwork1.iface.interfaceName)
 
         tryTest {
-            nsdShim.discoverServices(nsdManager, SERVICE_TYPE, NsdManager.PROTOCOL_DNS_SD,
+            nsdShim.discoverServices(nsdManager, serviceType, NsdManager.PROTOCOL_DNS_SD,
                     NetworkRequest.Builder()
                             .removeCapability(NET_CAPABILITY_TRUSTED)
                             .addTransportType(TRANSPORT_TEST)
@@ -593,7 +593,7 @@
         assumeTrue(TestUtils.shouldTestTApis())
 
         val si = NsdServiceInfo()
-        si.serviceType = SERVICE_TYPE
+        si.serviceType = serviceType
         si.serviceName = this.serviceName
         si.port = 12345 // Test won't try to connect so port does not matter
 
@@ -603,7 +603,7 @@
             val resolveRecord = NsdResolveRecord()
 
             val discoveryRecord = NsdDiscoveryRecord()
-            nsdManager.discoverServices(SERVICE_TYPE, NsdManager.PROTOCOL_DNS_SD, discoveryRecord)
+            nsdManager.discoverServices(serviceType, NsdManager.PROTOCOL_DNS_SD, discoveryRecord)
 
             val foundInfo1 = discoveryRecord.waitForServiceDiscovered(
                     serviceName, testNetwork1.network)
@@ -618,7 +618,7 @@
             val cb = resolveRecord.expectCallback<ServiceResolved>()
             cb.serviceInfo.let {
                 // Resolved service type has leading dot
-                assertEquals(".$SERVICE_TYPE", it.serviceType)
+                assertEquals(".$serviceType", it.serviceType)
                 assertEquals(registeredInfo.serviceName, it.serviceName)
                 assertEquals(si.port, it.port)
                 assertEquals(testNetwork1.network, nsdShim.getNetwork(it))
@@ -637,7 +637,7 @@
         assumeTrue(TestUtils.shouldTestTApis())
 
         val si = NsdServiceInfo()
-        si.serviceType = SERVICE_TYPE
+        si.serviceType = serviceType
         si.serviceName = this.serviceName
         si.network = testNetwork1.network
         si.port = 12345 // Test won't try to connect so port does not matter
@@ -651,7 +651,7 @@
 
         tryTest {
             // Discover service on testNetwork1.
-            nsdShim.discoverServices(nsdManager, SERVICE_TYPE, NsdManager.PROTOCOL_DNS_SD,
+            nsdShim.discoverServices(nsdManager, serviceType, NsdManager.PROTOCOL_DNS_SD,
                 testNetwork1.network, Executor { it.run() }, discoveryRecord)
             // Expect that service is found on testNetwork1
             val foundInfo = discoveryRecord.waitForServiceDiscovered(
@@ -659,14 +659,14 @@
             assertEquals(testNetwork1.network, nsdShim.getNetwork(foundInfo))
 
             // Discover service on testNetwork2.
-            nsdShim.discoverServices(nsdManager, SERVICE_TYPE, NsdManager.PROTOCOL_DNS_SD,
+            nsdShim.discoverServices(nsdManager, serviceType, NsdManager.PROTOCOL_DNS_SD,
                 testNetwork2.network, Executor { it.run() }, discoveryRecord2)
             // Expect that discovery is started then no other callbacks.
             discoveryRecord2.expectCallback<DiscoveryStarted>()
             discoveryRecord2.assertNoCallback()
 
             // Discover service on all networks (not specify any network).
-            nsdShim.discoverServices(nsdManager, SERVICE_TYPE, NsdManager.PROTOCOL_DNS_SD,
+            nsdShim.discoverServices(nsdManager, serviceType, NsdManager.PROTOCOL_DNS_SD,
                 null as Network? /* network */, Executor { it.run() }, discoveryRecord3)
             // Expect that service is found on testNetwork1
             val foundInfo3 = discoveryRecord3.waitForServiceDiscovered(
@@ -684,7 +684,7 @@
     fun testNsdManager_RegisterServiceNameWithNonStandardCharacters() {
         val serviceNames = "^Nsd.Test|Non-#AsCiI\\Characters&\\ufffe テスト 測試"
         val si = NsdServiceInfo().apply {
-            serviceType = SERVICE_TYPE
+            serviceType = this@NsdManagerTest.serviceType
             serviceName = serviceNames
             port = 12345 // Test won't try to connect so port does not matter
         }
@@ -698,7 +698,7 @@
             // Discover that service name.
             val discoveryRecord = NsdDiscoveryRecord()
             nsdManager.discoverServices(
-                SERVICE_TYPE, NsdManager.PROTOCOL_DNS_SD, discoveryRecord
+                serviceType, NsdManager.PROTOCOL_DNS_SD, discoveryRecord
             )
             val foundInfo = discoveryRecord.waitForServiceDiscovered(serviceNames)