Removes metric requirement for ISM Rollup as it's not required

[dbbaughe]

Issue #, if available:

Description of changes:

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov]

Codecov Report

Merging #389 (354fe16) into master (1aa245e) will decrease coverage by 0.26%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master     #389      +/-   ##
============================================
- Coverage     76.77%   76.51%   -0.27%     
+ Complexity     1462     1460       -2     
============================================
  Files           188      188              
  Lines          7334     7333       -1     
  Branches       1188     1187       -1     
============================================
- Hits           5631     5611      -20     
- Misses         1060     1078      +18     
- Partials        643      644       +1     

Impacted Files	Coverage Δ	Complexity Δ
...icsearch/indexmanagement/rollup/model/ISMRollup.kt	94.44% <ø> (-0.06%)	29.00 <0.00> (-2.00)
...statemanagement/model/destination/CustomWebhook.kt	65.21% <0.00%> (-28.99%)	12.00% <0.00%> (-2.00%)
...anagement/indexstatemanagement/model/Transition.kt	64.61% <0.00%> (-3.08%)	5.00% <0.00%> (ø%)
...nt/indexstatemanagement/model/destination/Chime.kt	54.54% <0.00%> (+13.63%)	4.00% <0.00%> (+2.00%)

---

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 1aa245e...0eb13da. Read the comment docs.

[thalurur]

Thanks for correcting this