[Test🧪] Add unit tests for TimerMetricsSerializeWrapper

[mxsm]

Prerequisites

• I have searched existing test issues

Test Scope

Module: rocketmq-remoting
File: src/protocol/body/timer_metrics_serialize_wrapper.rs
Current Coverage: Unknown
Target Coverage: 80%+

Test Cases

The following test scenarios need to be implemented for TimerMetricsSerializeWrapper:

• Test struct field initialization
• Test all getter methods return correct values
• Test all setter methods update values correctly
• Test serialization to JSON
• Test deserialization from JSON
• Test serialization/deserialization roundtrip
• Test Default trait implementation (if derived)
• Test Clone trait implementation (if derived)
• Test with HashMap of Metric entries
• Test with DataVersion field
• Test adding/removing metrics
• Test with empty metrics HashMap
• Test with multiple Metric entries

Willing to contribute?

• I can submit a PR for this