Fix ContentTypeId conflict

[CrazyHZM]

What is the purpose of the change

Fix Serialization ContentTypeId conflict between avro protocol and protocoluff protocol #3926

Brief changelog

XXXXX

Verifying this change

XXXXX

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[codecov-io]

Codecov Report

Merging #3967 into master will increase coverage by <.01%.
The diff coverage is 66.66%.

@@             Coverage Diff              @@
##             master    #3967      +/-   ##
============================================
+ Coverage     63.58%   63.58%   +<.01%     
  Complexity      100      100              
============================================
  Files           720      720              
  Lines         31838    31839       +1     
  Branches       5113     5114       +1     
============================================
+ Hits          20245    20246       +1     
  Misses         9273     9273              
  Partials       2320     2320

Impacted Files	Coverage Δ	Complexity Δ
...c/main/java/org/apache/dubbo/common/Constants.java	93.33% <ø> (ø)	0 <0> (ø)	⬇️
.../serialize/protostuff/ProtostuffSerialization.java	60% <0%> (ø)	0 <0> (ø)	⬇️
.../apache/dubbo/remoting/transport/CodecSupport.java	77.77% <0%> (-3%)	0 <0> (ø)
...dubbo/common/serialize/kryo/KryoSerialization.java	60% <0%> (ø)	0 <0> (ø)	⬇️
...dubbo/common/serialize/java/JavaSerialization.java	80% <100%> (ø)	0 <0> (ø)	⬇️
...mmon/serialize/hessian2/Hessian2Serialization.java	80% <100%> (ø)	0 <0> (ø)	⬇️
...dubbo/common/serialize/avro/AvroSerialization.java	100% <100%> (ø)	0 <0> (ø)	⬇️
...mon/serialize/java/CompactedJavaSerialization.java	80% <100%> (ø)	0 <0> (ø)	⬇️
.../serialize/nativejava/NativeJavaSerialization.java	80% <100%> (ø)	0 <0> (ø)	⬇️
...mmon/serialize/fastjson/FastJsonSerialization.java	100% <100%> (ø)	0 <0> (ø)	⬇️
... and 10 more

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[beiwei30]

this is wrong, avro is 10...

[beiwei30]

public static final byte AVRO_SERIALIZATION_ID = 11 should be better

[CrazyHZM]

public static final byte AVRO_SERIALIZATION_ID = 11 should be better

What are the uses of 1 and 5 here?

[beiwei30]

let's simply leave it as is. I believe the original intention is: 1, 2, 4, 8, 16...

[CrazyHZM]

I have modified it.

[beiwei30]

pls. check my comments.

[beiwei30]

LGTM.

[cvictory]

Maybe you can define a sub-constant class. What do you think?

[kun-song]

+1 for a specific constants class

[CrazyHZM]

I think this suggestion is good, I will modify it later.