android library增加productFlavors,並在app module 引用某個flavors

library中增加productFlavors和appmodule中類似

productFlavors{
    buildConfigField "boolean", "ReadTestServer", "false"
    sdkDemoTest{
        buildConfigField "boolean", "ReadTestServer", "true"
        buildConfigField "boolean", "SDKDemo", "true"
    }
    sdkDemoOfficial{
        buildConfigField "boolean", "SDKDemo", "true"
    }
}

這時如果app module中按照正常的 

compile project(':app'） 會發現無法引用到項目，編譯會發現library中的所有類都無法找到

需要使用如下方式指定使用的flavors進行引用：

compile project(path: ':app',configuration:'sdkDemoOfficialDebug')

或 

compile project(path: ':app',configuration:'sdkDemoOfficialRelease')