Android Studio‘Library projects cannot set applicationId’

Library projects cannot set applicationId. applicationId is set to 'com.biumall.usercenter' in default config.

    defaultConfig {
        if (!isUserCenterLib.toBoolean()) {
            //library时不需applicationId
            applicationId "com.biumall.usercenter"
        }
        minSdkVersion 21
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }