[Bug]: 两个FlutterActivity中间有原生Activity跳转的问题

### 请描述遇到的问题，以及您所期望的正确的结果

FlutterActivityA （Flutter内部a-b-c跳转）-> ActivityB -> FlutterActivityC 依次返回FlutterActivityA页面的a b都不能渲染出来

### 请说明如何操作会遇到上述问题

FlutterActivityA （Flutter内部a-b-c跳转）-> ActivityB -> FlutterActivityC
依次返回FlutterActivityA页面的a b都不能渲染出来

### 在下面填入关键复现代码

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### 复现的平台

Both

### Flutter SDK版本

3.19.6

### FlutterBoost版本

4.6.5

### 是否延迟初始化FlutterBoost

No

### 解决方案

Start by reproducing the FlutterActivityA → ActivityB → FlutterActivityC flow with Flutter 3.19.6 and FlutterBoost 4.6.5, checking the behavior when returning to FlutterActivityA. The issue provides no reproduction code or named files, so trace FlutterBoost's activity navigation and rendering behavior on both platforms. Done means the a and b pages render correctly after returning to FlutterActivityA.

Written by the indexing model from the issue text.