Update AbstractDataBufferAllocatingTests

We are passing custom values to the constructor of PooledByteBufAllocator in
tests in order to turn of caching. This is based on:
https://github.com/netty/netty/issues/5275#issuecomment-220547057

Netty 4.1.52 has significant changes in PooledByteBufAllocator:
https://github.com/netty/netty/pull/10267

After the changes, our current value for maxOrder=2, which results in
chunkSize=16K, causes an assert failure in PoolChunk where the runSize
exceeds the chunkSize.

spring-core/src/testFixtures/java/org/springframework/core/testfixture/io/buffer/AbstractDataBufferAllocatingTests.java

@@ -159,11 +159,12 @@ public abstract class AbstractDataBufferAllocatingTests {
 					new NettyDataBufferFactory(new UnpooledByteBufAllocator(true))),
 			arguments("NettyDataBufferFactory - UnpooledByteBufAllocator - preferDirect = false",
 					new NettyDataBufferFactory(new UnpooledByteBufAllocator(false))),
-			// disable caching for reliable leak detection, see https://github.com/netty/netty/issues/5275
+			// 1) Disable caching for reliable leak detection, see https://github.com/netty/netty/issues/5275
+			// 2) maxOrder is 4 (vs default 11) but can be increased if necessary
 			arguments("NettyDataBufferFactory - PooledByteBufAllocator - preferDirect = true",
-					new NettyDataBufferFactory(new PooledByteBufAllocator(true, 1, 1, 4096, 2, 0, 0, 0, true))),
+					new NettyDataBufferFactory(new PooledByteBufAllocator(true, 1, 1, 4096, 4, 0, 0, 0, true))),
 			arguments("NettyDataBufferFactory - PooledByteBufAllocator - preferDirect = false",
-					new NettyDataBufferFactory(new PooledByteBufAllocator(false, 1, 1, 4096, 2, 0, 0, 0, true))),
+					new NettyDataBufferFactory(new PooledByteBufAllocator(false, 1, 1, 4096, 4, 0, 0, 0, true))),
 			arguments("DefaultDataBufferFactory - preferDirect = true",
 					new DefaultDataBufferFactory(true)),
 			arguments("DefaultDataBufferFactory - preferDirect = false",