[SDK] Fix BatchLogRecordProcessor to instrument shutdown

[marcalff]

Fixes #3261

Changes

Please provide a brief description of the changes here.

• In BatchLogRecordProcessor, used the same coding pattern in BatchSpanProcessor, so that proper OnEnd() instrumentation is called on shutdown.

For significant contributions please make sure you have completed the following items:

• CHANGELOG.md updated for non-trivial changes
• Unit tests have been added
• Changes in public API reviewed

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 87.92%. Comparing base (edb8937) to head (75570bb).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3262      +/-   ##
==========================================
+ Coverage   87.91%   87.92%   +0.01%     
==========================================
  Files         201      201              
  Lines        6385     6386       +1     
==========================================
+ Hits         5613     5614       +1     
  Misses        772      772              

Files with missing lines	Coverage Δ
sdk/src/logs/batch_log_record_processor.cc	83.01% <100.00%> (+0.12%)	⬆️