Remove Play Store access without removing Play Services I have built AOSP for the kiddo's phone. My goal was to remove the Play Store so that he can't install games or other apps. 

However, we use Google Fi for our phone service, which requires Google Play services to function. That alone isn't a big deal using Open Gapps. However, I would like to remove the Play Store, but keep Google play services so that the Fi app can be used.

From what I can tell, Play Store and Play Services seem to be married (i.e., removing Phonesky.apk with Titanium Backup removes both the Play Store and Play Services).

Is there any way that I can remove the Play Store, but keep access to Play Services so that the phone can still register through Google Fi?

Note: this is on a rooted Pixel 1. AOSP is not a strict requirement, just something I was trying to use to solve my problem. If it can be done on, i.e., the stock ROM that'd be great too.

Note 2: I realize the Play Store can be disabled in the apps settings, but this kid is smart enough to figure that one out. I also tried hiding it in Nova Launcher Prime, but it still shows up in search results within the launcher.
For my purpose, the following works in adb shell (as root):

pm disable com.android.vending


Of course, now I need to figure out a way to make this persist over a factory reset...