Cleanup the code to make it buildable with androidx annotations

Test: m
Change-Id: I2d4fd9760d07ea20a5ed83d9ed03ce26b1d6e162
diff --git a/service-t/src/com/android/server/connectivity/mdns/MdnsConstants.java b/service-t/src/com/android/server/connectivity/mdns/MdnsConstants.java
index ce5f540..0c32cf1 100644
--- a/service-t/src/com/android/server/connectivity/mdns/MdnsConstants.java
+++ b/service-t/src/com/android/server/connectivity/mdns/MdnsConstants.java
@@ -16,18 +16,13 @@
 
 package com.android.server.connectivity.mdns;
 
-import static com.android.internal.annotations.VisibleForTesting.Visibility.PACKAGE;
-
 import static java.nio.charset.StandardCharsets.UTF_8;
 
-import com.android.internal.annotations.VisibleForTesting;
-
 import java.net.InetAddress;
 import java.net.UnknownHostException;
 import java.nio.charset.Charset;
 
 /** mDNS-related constants. */
-@VisibleForTesting(visibility = PACKAGE)
 public final class MdnsConstants {
     public static final int MDNS_PORT = 5353;
     // Flags word format is:
diff --git a/service-t/src/com/android/server/connectivity/mdns/MdnsServiceTypeClient.java b/service-t/src/com/android/server/connectivity/mdns/MdnsServiceTypeClient.java
index 3b5193a..b15defd 100644
--- a/service-t/src/com/android/server/connectivity/mdns/MdnsServiceTypeClient.java
+++ b/service-t/src/com/android/server/connectivity/mdns/MdnsServiceTypeClient.java
@@ -29,7 +29,6 @@
 import android.util.ArraySet;
 import android.util.Pair;
 
-import com.android.internal.annotations.GuardedBy;
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.net.module.util.CollectionUtils;
 import com.android.net.module.util.SharedLog;
@@ -93,6 +92,7 @@
         }
 
         @Override
+        @SuppressWarnings("FutureReturnValueIgnored")
         public void handleMessage(Message msg) {
             switch (msg.what) {
                 case EVENT_START_QUERYTASK: {
@@ -278,6 +278,7 @@
      * @param listener      The {@link MdnsServiceBrowserListener} to register.
      * @param searchOptions {@link MdnsSearchOptions} contains the list of subtypes to discover.
      */
+    @SuppressWarnings("FutureReturnValueIgnored")
     public void startSendAndReceive(
             @NonNull MdnsServiceBrowserListener listener,
             @NonNull MdnsSearchOptions searchOptions) {
@@ -841,7 +842,6 @@
         return minRemainingTtl == Long.MAX_VALUE ? 0 : minRemainingTtl;
     }
 
-    @GuardedBy("lock")
     @NonNull
     private void scheduleNextRun(@NonNull QueryTaskConfig nextRunConfig,
             long minRemainingTtl,