Add additional unit tests for functions in constants.go

[timl3136]

What changed?
Add unit tests for functions in constants.go

Why?
improve coverage

How did you test it?
unit tests

Potential risks

Release notes

Documentation Changes

[coveralls]

Pull Request Test Coverage Report for Build 018e0fa8-60f0-48ba-b947-31f6cd133c5f

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 86 unchanged lines in 19 files lost coverage.
• Overall coverage increased (+0.02%) to 63.131%

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Files with Coverage Reduction	New Missed Lines	%
service/matching/taskGC.go	1	97.37%
common/membership/hashring.go	2	82.23%
common/peerprovider/ringpopprovider/config.go	2	81.58%
common/persistence/sql/sqlplugin/mysql/db.go	2	83.33%
common/persistence/sql/sqlplugin/mysql/task.go	2	73.68%
common/task/fifo_task_scheduler.go	2	87.63%
common/task/weighted_round_robin_task_scheduler.go	2	88.06%
service/history/execution/mutable_state_builder.go	2	68.74%
service/history/task/fetcher.go	2	85.05%
service/history/task/timer_task_executor_base.go	2	78.38%

Totals
Change from base Build 018e0f91-436c-45b1-853d-c77bc9d2af65:	0.02%
Covered Lines:	92595
Relevant Lines:	146671

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💛 - Coveralls