关于v3.0-preview.9 iOS集成 pod中遇到的问题

按照https://github.com/alibaba/flutter_boost/blob/master/docs/install.md文档操作， flutter_module引入
```
flutter_boost:
git:
url: 'https://github.com/alibaba/flutter_boost.git'
ref: 'v3.0-preview.9'
```
原生iOS项目Podfile 加入代码

```
platform :ios, '10.0'

flutter_application_path = '../flutter_module'
load File.join(flutter_application_path, '.ios', 'Flutter', 'podhelper.rb')

def shared_pod
pod 'AFNetworking'
pod 'MJExtension'
pod 'SDWebImage'
pod 'MJRefresh'
...

end

target 'new_studentApp' do

use_frameworks!
install_all_flutter_pods(flutter_application_path)

shared_pod
end
```

执行pod install

之后build iOS原生项目包多处原本正常的头文件未找到错误
原生iOS项目是OC混合Swift，在集成flutter_boost3.0之前，pod依赖的库是正常，不存在头文件未找到的情况，项目运行正常，故求助是否flutter_boost3.0 pod install 新增的依赖，如FMDB，FlutterPluginRegistrant..这些导致某种异常。

Read docs/install.md and the native iOS Podfile, focusing on the flutter_boost v3.0-preview.9 integration and the added pod dependencies. Reproduce with pod install and an iOS build, recording the exact missing-header errors shown in the screenshots; done means the cause is isolated and the previously working Objective-C/Swift dependencies build successfully.

Written by the indexing model from the issue text.