fix: Make Metrics harvest only on EoL for new Harvester

[cwli24]

Prevent Metrics feature from harvesting on interval after changes in v1.278.0. This reverts its behavior back to sending only final harvests.

Overview

Related Issue(s)

https://new-relic.atlassian.net/browse/NR-356543

Testing

New component test added for this case

[github-actions]

Asset Size Report

Merging this pull request will result in the following asset size changes:

Agent	Asset	Previous Size	New Size	Diff
lite	loader	29.75 kB / 10.79 kB (gzip)	29.75 kB / 10.79 kB (gzip)	0% / 0.02% (gzip)
lite	async-chunk	52.4 kB / 17.01 kB (gzip)	52.46 kB / 17.03 kB (gzip)	0.1% / 0.09% (gzip)
pro	loader	51.4 kB / 17.74 kB (gzip)	51.4 kB / 17.74 kB (gzip)	0% / -0.01% (gzip)
pro	async-chunk	99.23 kB / 30.3 kB (gzip)	99.29 kB / 30.32 kB (gzip)	0.05% / 0.06% (gzip)
spa	loader	59.02 kB / 20.07 kB (gzip)	59.02 kB / 20.07 kB (gzip)	0% / 0% (gzip)
spa	async-chunk	113.95 kB / 34.64 kB (gzip)	114 kB / 34.66 kB (gzip)	0.05% / 0.05% (gzip)

[metal-messiah]

Approved once tests run

[github-actions]

Last ran on January 08, 2025 12:30:53 CST
Checking merge of (37ae0a2) into main (c22f253)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 88.58%. Comparing base (c22f253) to head (37ae0a2).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1311      +/-   ##
==========================================
+ Coverage   88.54%   88.58%   +0.04%     
==========================================
  Files         170      170              
  Lines        7325     7325              
  Branches     1480     1481       +1     
==========================================
+ Hits         6486     6489       +3     
+ Misses        723      720       -3     
  Partials      116      116              

Flag	Coverage Δ
integration-tests	91.28% <100.00%> (ø)
unit-tests	79.67% <100.00%> (+0.09%)	⬆️

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