[BUG] <After changing the app-tomcat.yml memory_pool unit to MB, the collected data switches back and forth between B and MB units>

[rbsrcy]

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

app-tomcat.yml memory_pool 单位改为MB后（#1268 ），采集数据在B和MB单位来回切换。可能和TDengine保存历史数据是B单位有关。

Expected Behavior

正常应该使用MB单位进行采集和现实数据，实际上会在采集数据在B和MB单位来回切换

Steps To Reproduce

1、使用原始配置tomcat监控，并启用监控
2、 修改tomcat 配置模版 memory_pool 单位改为MB
3、重新启用监控

Environment

HertzBeat version(s):v1.4.1

Debug logs

No response

Anything else?

No response