fix: sessionId in first open and session start events

[zhu-xiaowei]

• PR title and description conform to Pull Request guidelines.

Description of changes:

1. fix sessionId in first open and session start events

How did you test these changes?
added test case for assert first open and session start event have the same sessionid

Documentation update required?

• No
• Yes (Please include a PR link for the documentation update)

General Checklist

• Added Unit Tests

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 86.49%. Comparing base (f9d9e57) to head (76e068c).
Report is 16 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main      #68      +/-   ##
============================================
- Coverage     87.42%   86.49%   -0.94%     
  Complexity      458      458              
============================================
  Files            42       42              
  Lines          1686     1688       +2     
  Branches        152      154       +2     
============================================
- Hits           1474     1460      -14     
- Misses          135      150      +15     
- Partials         77       78       +1     

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