Fix an import deprecation warning

[bryant1410]

What does this PR do?

Fix an import deprecation warning (collections -> collections.abc for some classes).

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[codecov]

Codecov Report

Merging #2746 into master will not change coverage.
The diff coverage is 100%.

@@          Coverage Diff           @@
##           master   #2746   +/-   ##
======================================
  Coverage      90%     90%           
======================================
  Files          82      82           
  Lines        6791    6791           
======================================
  Hits         6131    6131           
  Misses        660     660