My current phone (Pixel 2 XL) is running the build PQ1A.181105.017.A1. According to [source.android.com](https://source.android.com/setup/start/build-numbers), that means it was build from branch android-9.0.0\_r16. Looking at a source file from that particular branch, for example [SignalStrength.java](https://android.googlesource.com/platform/frameworks/base/+/android-9.0.0_r16/telephony/java/android/telephony/SignalStrength.java), there is a public method called getWcdmaRscp(). However, it appears this method was added after SDK version 28 was released, so if I try to call it from my app in Android Studio when targeting 28, it doesn't build.

I'm guessing my phone will gladly allow me to call the method in question, so how do I setup my Android Studio to be able to build against that version of the framework?

It appears I would need a new framework.jar, but where can I find that? Please don't tell me I need to download and build the entire AOSP thing locally.