android library增加productFlavors,并在app module 引用某个flavors

library中增加productFlavors和appmodule中类似

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

这时如果app module中按照正常的 

compile project(':app'） 会发现无法引用到项目，编译会发现library中的所有类都无法找到

需要使用如下方式指定使用的flavors进行引用：

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