Sending notification when failing to acquire lock

[Angie-Zhang]

Issue #, if available:
#666

This PR will be reviewed and merged after #667 merged.

CheckList:

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[codecov-commenter]

Codecov Report

Merging #668 (3373c57) into main (2241a29) will decrease coverage by 0.08%.
The diff coverage is 41.86%.

@@             Coverage Diff              @@
##               main     #668      +/-   ##
============================================
- Coverage     74.71%   74.63%   -0.08%     
- Complexity     2790     2795       +5     
============================================
  Files           366      366              
  Lines         16365    16425      +60     
  Branches       2346     2358      +12     
============================================
+ Hits          12227    12259      +32     
- Misses         2844     2864      +20     
- Partials       1294     1302       +8     

Files	Coverage Δ
...ent/indexstatemanagement/util/NotificationUtils.kt	0.00% <0.00%> (ø)
...agement/indexstatemanagement/ManagedIndexRunner.kt	46.04% <43.37%> (-0.73%)	⬇️

... and 7 files with indirect coverage changes

[dblock]

@Angie-Zhang @bowenlan-amzn Want to rebase and finish this?