Increase the timeout of ChannelDeregistrationTest

Motivation:

When a thread-local random is used first time, it tries to get the
initial seed uniquifier from SecureRandom, and it sometimes takes time
for the system to have enough entropy.

In ChannelDeregistrationTest, the retrieval of the initial seed
uniquifier takes place lazily when a new channel is created, and it
blocks the channel creation for more than 2 seconds, resulting in test
timeouts.

Modifications:

Increase the timeout of the tests to 5 seconds, because the timeout of
the initial seed uniquifier retrieval is 3 seconds.

Result:

Less flakey tests

transport/src/test/java/io/netty/channel/ChannelDeregistrationTest.java

@@ -73,7 +73,7 @@ public class ChannelDeregistrationTest {
      * It's important to make sure that they are preserved during and after
      * {@linkplain io.netty.channel.Channel#deregister()}.
      */
-    @Test(timeout = 2000)
+    @Test(timeout = 5000)
     public void testDeregisterFromDifferentEventExecutorGroup() throws Exception  {
         final AtomicBoolean handlerExecuted1 = new AtomicBoolean();
         final AtomicBoolean handlerExecuted2 = new AtomicBoolean();
@@ -128,7 +128,7 @@ public class ChannelDeregistrationTest {
      * Make sure the {@link EventLoop} and {@link ChannelHandlerInvoker} accessible from within a
      * {@link ChannelHandler} are wrapped by a {@link PausableEventExecutor}.
      */
-    @Test(timeout = 2000)
+    @Test(timeout = 5000)
     public void testWrappedEventLoop() throws Exception {
         final AtomicBoolean channelActiveCalled1 = new AtomicBoolean();
         final AtomicBoolean channelActiveCalled2 = new AtomicBoolean();
@@ -205,7 +205,7 @@ public class ChannelDeregistrationTest {
     /**
      * See https://github.com/netty/netty/issues/2814
      */
-    @Test(timeout = 1000)
+    @Test(timeout = 5000)
     public void testPromise() {
         ChannelHandler handler = new TestChannelHandler1();
         AbstractChannel ch = new EmbeddedChannel(handler);