Support serialized checkpoint loading

[jjenniferdai]

What does this PR do?

Fixes #9406

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[codecov]

Codecov Report

Merging #9605 (701fb6a) into master (6feda08) will decrease coverage by 4%.
The diff coverage is 38%.

@@           Coverage Diff           @@
##           master   #9605    +/-   ##
=======================================
- Coverage      93%     89%    -4%     
=======================================
  Files         179     179            
  Lines       15805   15824    +19     
=======================================
- Hits        14648   14030   -618     
- Misses       1157    1794   +637     

[tchaton]

LGTM !