[Backport 2.1] Snapshot management default date format in snapshot name

[opensearch-trigger-bot]

Backport 1c9f232 from #392

[codecov-commenter]

Codecov Report

Merging #393 (195adf9) into 2.1 (279f7a6) will decrease coverage by 0.06%.
The diff coverage is 58.33%.

@@             Coverage Diff              @@
##                2.1     #393      +/-   ##
============================================
- Coverage     75.80%   75.74%   -0.07%     
+ Complexity     2468     2461       -7     
============================================
  Files           313      313              
  Lines         14423    14425       +2     
  Branches       2231     2229       -2     
============================================
- Hits          10934    10926       -8     
- Misses         2243     2255      +12     
+ Partials       1246     1244       -2     

Impacted Files	Coverage Δ
...arch/indexmanagement/snapshotmanagement/SMUtils.kt	72.28% <58.33%> (+3.99%)	⬆️
...nt/indexstatemanagement/model/destination/Chime.kt	55.55% <0.00%> (-22.23%)	⬇️
...xmanagement/indexstatemanagement/util/StepUtils.kt	85.39% <0.00%> (-2.25%)	⬇️
.../action/explain/TransportExplainTransformAction.kt	70.78% <0.00%> (-2.25%)	⬇️
...ent/indexstatemanagement/util/ManagedIndexUtils.kt	76.10% <0.00%> (-1.77%)	⬇️
...gement/indexstatemanagement/action/ShrinkAction.kt	70.58% <0.00%> (-1.48%)	⬇️
.../rollup/action/start/TransportStartRollupAction.kt	71.76% <0.00%> (-1.18%)	⬇️
...nt/rollup/action/stop/TransportStopRollupAction.kt	76.47% <0.00%> (-1.18%)	⬇️
...nt/indexstatemanagement/ManagedIndexCoordinator.kt	68.71% <0.00%> (-0.59%)	⬇️
...earch/indexmanagement/transform/model/Transform.kt	85.47% <0.00%> (-0.43%)	⬇️
... and 2 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 279f7a6...195adf9. Read the comment docs.