(1/n) tests: Use strategy flag instead of accelerator for training strategies

[kaushikb11]

What does this PR do?

Part of #9932

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[codecov]

Codecov Report

Merging #9931 (7dfbb33) into master (a002f87) will decrease coverage by 0%.
The diff coverage is n/a.

@@          Coverage Diff           @@
##           master   #9931   +/-   ##
======================================
- Coverage      93%     93%   -0%     
======================================
  Files         179     179           
  Lines       15803   15833   +30     
======================================
+ Hits        14647   14673   +26     
- Misses       1156    1160    +4     

[tchaton]

LGTM !

[carmocca]

Some tests are failing