Re-enable kafka consumer test

[taylanisikdemir]

What changed?
TestNewConsumer was flaky so it was disabled recently. Underlying issues are addressed in #5712 so re-enabling it.

How did you test it?
go test -timeout 60s -run ^TestNewConsumer$ github.com/uber/cadence/common/messaging/kafka -v -count=100

[coveralls]

Pull Request Test Coverage Report for Build 018e4358-d6b0-4512-a8bb-f92b4086fdec

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 67 unchanged lines in 11 files lost coverage.
• Overall coverage increased (+0.009%) to 64.883%

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Files with Coverage Reduction	New Missed Lines	%
common/task/weighted_round_robin_task_scheduler.go	1	89.05%
service/history/task/timer_task_executor_base.go	2	78.38%
service/history/execution/mutable_state_util.go	2	78.48%
common/task/fifo_task_scheduler.go	3	84.54%
tools/cli/admin_db_decode_thrift.go	3	69.23%
service/history/queue/timer_gate.go	3	95.83%
common/persistence/nosql/nosqlplugin/cassandra/workflow.go	3	71.41%
service/history/task/fetcher.go	4	86.08%
service/history/task/transfer_standby_task_executor.go	6	86.6%
common/persistence/nosql/nosqlplugin/cassandra/workflow_parsing_utils.go	19	79.13%

Totals
Change from base Build 018e415e-6c2b-4c47-90b3-66581a8de24f:	0.009%
Covered Lines:	94584
Relevant Lines:	145777

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💛 - Coveralls