Android studio 报错 Unable to resolve dependency for ‘:app@releaseUnitTest/compileClasspath‘:

出现报错：

Unable to resolve dependency for ':app@debugAndroidTest/compileClasspath': Could not find any version that matches com.android.support:appcompat-v7:30.+.

解决方法：

删除app>>gradle下的

implementation 'com.android.support:appcompat-v7:30.+'