[Improve][Manager] Add unit test of HeartbeatController

[beatCao]

Description

What happened
add ut HeartbeatController

What you expected to happen
add ut HeartbeatController

How to reproduce
add ut HeartbeatController

Environment
add ut HeartbeatController

InLong Component
inlong-manager

InLong Component

InLong Manager

Are you willing to submit PR?

• Yes, I am willing to submit a PR!

Code of Conduct

• I agree to follow this project's Code of Conduct

[github-actions]

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