Add retry logic to gcs download script

[oxve]

b/211897434

[codecov]

Codecov Report

Merging #1471 (fb90673) into main (1e8fbb4) will decrease coverage by 0.02%.
Report is 11 commits behind head on main.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #1471      +/-   ##
==========================================
- Coverage   56.39%   56.37%   -0.02%     
==========================================
  Files        1902     1902              
  Lines       94597    94607      +10     
==========================================
- Hits        53345    53333      -12     
- Misses      41252    41274      +22     

see 11 files with indirect coverage changes

[oxve]

I tested this change on all internal windows devel builds and it passed.