Add CommonTemplateJvmInitializerIT

[Polber]

Follow up to #1744

Adds IT's to ensure that CommonTemplateJvmInitializer.beforeProcessing() is called by Dataflow worker before executing pipeline.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 15 lines in your changes missing coverage. Please review.

Project coverage is 42.30%. Comparing base (5be5817) to head (c0434f5).
Report is 1 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #1745      +/-   ##
============================================
- Coverage     42.31%   42.30%   -0.01%     
  Complexity     3181     3181              
============================================
  Files           794      796       +2     
  Lines         46244    46257      +13     
  Branches       4951     4950       -1     
============================================
+ Hits          19569    19571       +2     
- Misses        25077    25087      +10     
- Partials       1598     1599       +1     

Components	Coverage Δ
spanner-templates	63.69% <ø> (-0.01%)	⬇️
spanner-import-export	64.42% <ø> (-0.03%)	⬇️
spanner-live-forward-migration	74.97% <ø> (ø)
spanner-live-reverse-replication	51.84% <ø> (ø)
spanner-bulk-migration	82.79% <ø> (ø)

Files	Coverage Δ
...oud/teleport/plugin/TemplateDefinitionsParser.java	11.53% <0.00%> (+0.42%)	⬆️
...eport/templates/common/JvmInitializerTemplate.java	0.00% <0.00%> (ø)
...oud/teleport/v2/common/JvmInitializerTemplate.java	0.00% <0.00%> (ø)

... and 2 files with indirect coverage changes