Unable to Add Android Project-Level Plugin Dependencies to MAUI

I have tried multiple approaches, but I’m unable to add project-level build.gradle plugin dependencies to MAUI. Specifically, I attempted to integrate the [Instana Android Agent](https://github.com/instana/android-agent) into a MAUI project. While I was able to include the runtime library, the plugin itself could not be integrated.

```
plugins {
id("com.android.application")
id("com.instana.android-agent-plugin")
}
```

The plugin is included in the .aar package but is not applied when running MAUI. It seems that only build.gradle libraries at the app level are successfully included, while project-level plugin dependencies are not being applied.

I’m looking for a way to support the integration of project-level plugins in MAUI, as this behavior seems to affect other plugin-level injections as well.

首先复现 MAUI 与 Instana Android Agent 的集成，并将应用级库的行为与项目级 build.gradle 中的插件声明进行比较。检查 .aar 包的使用方式；当运行 MAUI 时应用了项目级 Android 插件，而不仅仅是运行时库时，即视为完成。

由索引模型根据 Issue 内容生成。