Fix for hanging issue on TPU Pod

[Liyang90]

What does this PR do?

Fixes #16843

Letting XLAEnvironment provide strategy.local_rank to the spawned processes, instead of using process_id. Avoid using strategy.local_rank outside of the spawned processes, as the XLA has not set that up.

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[codecov]

Codecov Report

Merging #16844 (1b55d33) into master (235e692) will decrease coverage by 22%.
The diff coverage is 27%.

Additional details and impacted files

@@            Coverage Diff            @@
##           master   #16844     +/-   ##
=========================================
- Coverage      82%      59%    -22%     
=========================================
  Files         437      413     -24     
  Lines       31528    31231    -297     
=========================================
- Hits        25777    18524   -7253     
- Misses       5751    12707   +6956