Fix errorprone 2.15.0 errors

Bug: 246761518
Test: RUN_ERROR_PRONE=true m javac-check lint-check dist
Change-Id: I4b81ef161fab5ee80a1713de87b89500a88e625e
diff --git a/Tethering/tests/unit/src/android/net/ip/IpServerTest.java b/Tethering/tests/unit/src/android/net/ip/IpServerTest.java
index f242227..5f4454b 100644
--- a/Tethering/tests/unit/src/android/net/ip/IpServerTest.java
+++ b/Tethering/tests/unit/src/android/net/ip/IpServerTest.java
@@ -271,6 +271,7 @@
                 mTestAddress);
     }
 
+    @SuppressWarnings("DoNotCall") // Ignore warning for synchronous to call to Thread.run()
     private void setUpDhcpServer() throws Exception {
         doAnswer(inv -> {
             final IDhcpServerCallbacks cb = inv.getArgument(2);
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringTest.java
index a36d67f..a468d82 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringTest.java
@@ -399,6 +399,7 @@
                     MacAddress.ALL_ZEROS_ADDRESS);
         }
 
+        @SuppressWarnings("DoNotCall") // Ignore warning for synchronous to call to Thread.run()
         @Override
         public void makeDhcpServer(String ifName, DhcpServingParamsParcel params,
                 DhcpServerCallbacks cb) {