Refactor the common test snapshot dirs creation code

[xiangzhu70]

Problem

Multiple test cases have duplicated common code for creating test snapshot dirs in PRE or POST states.

Summary of Changes

Created a function create_snapshot_dirs_for_tests to refactor the common code for creating test snapshot dirs in any numbers of PRE or POST states.

Fixes #

[codecov]

Codecov Report

Merging #31223 (074dd57) into master (f066ea9) will decrease coverage by 0.1%.
The diff coverage is 100.0%.

@@            Coverage Diff            @@
##           master   #31223     +/-   ##
=========================================
- Coverage    81.5%    81.5%   -0.1%     
=========================================
  Files         729      729             
  Lines      206466   206425     -41     
=========================================
- Hits       168366   168296     -70     
- Misses      38100    38129     +29