[BEAM-12588] Multimap user state proto changes

[kileys]

Add multimap user state to beam fn proto

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ValidatesRunner compliance status (on master branch)

Lang	ULR	Dataflow	Flink	Samza	Spark	Twister2
Go	---					---
Java
Python	---					---
XLang						---

Examples testing status on various runners

Lang	ULR	Dataflow	Flink	Samza	Spark	Twister2
Go	---	---	---	---	---	---	---
Java	---		---	---	---	---	---
Python	---	---	---	---	---	---	---
XLang	---	---	---	---	---	---	---

Post-Commit SDK/Transform Integration Tests Status (on master branch)

Go	Java	Python

Pre-Commit Tests Status (on master branch)

---	Java	Python	Go	Website	Whitespace	Typescript
Non-portable
Portable	---			---	---	---

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GitHub Actions Tests Status (on master branch)

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[kileys]

@lukecwik split out the proto

[codecov]

Codecov Report

Merging #15473 (dec0cbb) into master (823ab5a) will increase coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master   #15473      +/-   ##
==========================================
+ Coverage   83.74%   83.75%   +0.01%     
==========================================
  Files         443      443              
  Lines       60077    60089      +12     
==========================================
+ Hits        50312    50330      +18     
+ Misses       9765     9759       -6     

Impacted Files	Coverage Δ
...hon/apache_beam/portability/api/beam_fn_api_pb2.py	100.00% <0.00%> (ø)
...hon/apache_beam/runners/worker/bundle_processor.py	93.64% <0.00%> (+0.37%)	⬆️
...runners/interactive/display/pcoll_visualization.py	85.78% <0.00%> (+0.52%)	⬆️
...pache_beam/runners/interactive/interactive_beam.py	76.59% <0.00%> (+1.06%)	⬆️

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[kileys]

Run Java_Examples_Dataflow PreCommit

[lukecwik]

LGTM

[kileys]

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[kileys]

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[kileys]

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[kileys]

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[kileys]

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[lukecwik]

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