fix: RPCInvocation.ServiceKey use PATH_KEY instead of INTERFACE_KEY

[tweitjss]

What this PR does:

fix RPCInvocation.ServiceKey use INTERFACE_KEY which is different from java

Which issue(s) this PR fixes:

Fixes #1077

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

NONE

[codecov-io]

Codecov Report

Merging #1078 (bc375f7) into master (9b80e89) will decrease coverage by 0.13%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1078      +/-   ##
==========================================
- Coverage   59.57%   59.43%   -0.14%     
==========================================
  Files         268      268              
  Lines       13367    13367              
==========================================
- Hits         7963     7945      -18     
- Misses       4418     4435      +17     
- Partials      986      987       +1     

Impacted Files	Coverage Δ
remoting/kubernetes/watch.go	72.52% <0.00%> (-6.60%)	⬇️
remoting/kubernetes/registry_controller.go	46.12% <0.00%> (-5.31%)	⬇️
remoting/kubernetes/client.go	72.05% <0.00%> (-2.95%)	⬇️
remoting/kubernetes/listener.go	50.52% <0.00%> (ø)
cluster/cluster_impl/base_cluster_invoker.go	61.62% <0.00%> (+3.48%)	⬆️

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[zouyx]

can you help to add a test case for this change?

[zouyx]

What this PR does:

fix RPCInvocation.ServiceKey use INTERFACE_KEY which is different from java

Which issue(s) this PR fixes:

Fixes #1077

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

NONE

@tweitjss Thanks for you contribution.

[AlexStocks]

firstly, pls move ur target branch from master to 3.0. sencondly, pls add an ut.