AAPT: error: resource android:attr/fontVariationSettings not found

Android Studio中提示的错误Log:

/Users/lijiangping/.gradle/caches/transforms-1/files-1.1/appcompat-v7-27.1.1.aar/c85964a61f36e1b83cfed8dc0b27cbc1/res/values/values.xml:251:5-69: AAPT: error: resource android:attr/fontVariationSettings not found.
    
/Users/lijiangping/.gradle/caches/transforms-1/files-1.1/appcompat-v7-27.1.1.aar/c85964a61f36e1b83cfed8dc0b27cbc1/res/values/values.xml:251:5-69: AAPT: error: resource android:attr/ttcIndex not found.

引起的原因：项目中引入了多个aar，每个aar对应了不同的appcompat-v7版本，为了不引起错误，我们会设置force某个版本，但是问题就在这边，需要设置最高版本保证其他aar中引用的高资源内容不会因为我们设置低版本而出错。

/Users/lijiangping/MyProject/PP/framework/build.gradle: Error: All com.android.support libraries must use the exact same version specification (mixing versions can lead to runtime crashes). Found versions 28.0.0, 27.1.1, 25.2.0 . Examples include com.android.support:collections:28.0.0 and com.android.support:animated-vector-drawable:27.1.1 [GradleCompatible]

因此我们需要将我们的appcompat-v7版本force为这些aar中最高的版本：28.0.0

在build.gradle中加入：

configurations.all {
    resolutionStrategy.eachDependency { DependencyResolveDetails details ->
        def requested = details.requested
        if (requested.group == 'com.android.support') {
            if (!requested.name.startsWith("multidex")) {
                details.useVersion '28.0.0'
            }
        }
    }
}