Failed to resolve: android.arch.

repositories {
    maven {
        url 'https://maven.google.com'
        // Alternative URL is 'https://dl.google.com/dl/android/maven2/'
    }
}
注意下面那个注释，没错，只要把maven换成如下的

   url 'https://maven.google.com'   换为       url "https://dl.google.com/dl/android/maven2/" 

参考Failed to resolve: android.arch.lifecycle:extensions:1.0.0-alpha4问题解决