Fix: CUS-1729 fix export type

[emmaLP]

JIRA ticket link/s

• CUS-1729

Summary of changes

1. Updating export type in comments as it was not exposing the functions of the BufferedMetricsLogger with the previous return type
2. Adding a call to increment a metric on a test to ensure they are exported correctly

Additional Info

[codacy-production]

Coverage summary from Codacy

See diff coverage on Codacy

Coverage variation	Diff coverage
✅ +0.00% (target: -1.00%)	✅ ∅

Coverage variation details

	Coverable lines	Covered lines	Coverage
Common ancestor commit (6a4c0e8)	56	56	100.00%
Head commit (e341eeb)	56 (+0)	56 (+0)	100.00% (+0.00%)

Coverage variation is the difference between the coverage for the head and common ancestor commits of the pull request branch: <coverage of head commit> - <coverage of common ancestor commit>

Diff coverage details

	Coverable lines	Covered lines	Diff coverage
Pull request (#8)	0	0	∅ (not applicable)

Diff coverage is the percentage of lines that are covered by tests out of the coverable lines that the pull request added or modified: <covered lines added or modified>/<coverable lines added or modified> * 100%

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