Unity打包Android报错 UnityException: Adding Android library projects failed!

UnityException: Adding Android library projects failed!
UnityEditor.Android.AndroidLibraries.AddLibraryProject (System.String projectPropertiesPath)
UnityEditor.Android.AndroidLibraries.FindAndAddLibraryProjects (System.String searchPattern)
UnityEditor.Android.PostProcessor.Tasks.AddAndroidLibraries.Execute (UnityEditor.Android.PostProcessor.PostProcessorContext context)
UnityEditor.Android.PostProcessor.PostProcessRunner.RunAllTasks (UnityEditor.Android.PostProcessor.PostProcessorContext context)
错误原因
aar中的某些文件被删除了，比如aar中的AndroidManifest.xml被删除了。
解决方案
重新生成个aar