export 2.1.6 插件bug

[ILikeSoup]

Describe the bug

此处方法调用有问题，导致自定义组件样式导出图片时不生效。Object.keys 遍历的 property 是驼峰式，如：alignItems。但 getPropertyValue 方法的参数要是 align-items 才能获取到值。

Your Example Website or App

见bug描述

Steps to Reproduce the Bug or Issue

见bug描述

Expected behavior

见bug描述

Screenshots or Videos

No response

Platform

• OS: [e.g. macOS, Windows, Linux]
• Browser: [e.g. Chrome, Safari, Firefox]
• Version: [e.g. 2.11.1]
  见bug描述

Additional context

No response

[x6-bot]

👋 @ILikeSoup

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[NewByVector]

方便提个 PR？