Manifest merger failed : uses-sdk:minSdkVersion 8 cannot be smaller than version 9 declared in library

오류내용

Error:Execution failed for task ':app:processDebugManifest'.

> Manifest merger failed : uses-sdk:minSdkVersion 8 cannot be smaller than version 9 declared in library 

Suggestion: use tools:overrideLibrary="android.support.v4" to force usage

처리결과

build.gradle 파일에서

minSdkVersion 8

-> minSdkVersion 9

로 수정