api,netty: Fix TruthIncompatibleType

diff --git a/api/src/test/java/io/grpc/ClientInterceptorsTest.java b/api/src/test/java/io/grpc/ClientInterceptorsTest.java
index df5e800..555e940 100644
--- a/api/src/test/java/io/grpc/ClientInterceptorsTest.java
+++ b/api/src/test/java/io/grpc/ClientInterceptorsTest.java
@@ -329,7 +329,7 @@
     assertSame(listener, call.listener);
     assertSame(headers, call.headers);
     interceptedCall.sendMessage(null /*request*/);
-    assertThat(call.messages).containsExactly((Void) null /*request*/);
+    assertThat(call.messages).containsExactly((String) null);
     interceptedCall.halfClose();
     assertTrue(call.halfClosed);
     interceptedCall.request(1);
diff --git a/netty/src/test/java/io/grpc/netty/WriteBufferingAndExceptionHandlerTest.java b/netty/src/test/java/io/grpc/netty/WriteBufferingAndExceptionHandlerTest.java
index b3b536b..b99a938 100644
--- a/netty/src/test/java/io/grpc/netty/WriteBufferingAndExceptionHandlerTest.java
+++ b/netty/src/test/java/io/grpc/netty/WriteBufferingAndExceptionHandlerTest.java
@@ -345,7 +345,7 @@
     assertThat(chan.pipeline().context(handler)).isNull();
     assertThat(write.get().getClass()).isSameInstanceAs(Object.class);
     assertTrue(flush.get());
-    assertThat(chan.pipeline()).doesNotContain(handler);
+    assertThat(chan.pipeline().toMap().values()).doesNotContain(handler);
   }
 
   @Test