I've decompiled both the verifier package and the Play Store and found that
1-on Pre-Android 17 devices (where this app isn't pre-installed) the Play Store IS the one responsible to approving/denying installs as the developer verification permission DOESN'T exist on pre-Android 17 devices, which is why the Android Developer Verifier package has a backport service that the Play Store calls to verify installs
<service android:name="com.google.android.verifier.backport.impl.verification.BackportVerificationService" android:exported="true">
<intent-filter>
<action android:name="com.google.android.verifier.backport.VERIFY\_PACKAGE"/>
</intent-filter>
</service>



