Remove platform-signed apps from configurable cross profile apps

Most apps that declare the INTERACT_ACROSS_PROFILES permission do
not have it granted, but get the app-op instead. We do not
normally want platform-signed apps that are actually given the
permission to appear in the user-configurable section in Settings,
so we remove them from the return value of
canUserAttemptToConfigureInteractAcrossProfiles in this CL.

Note that OEM can choose to allow some platform-signed apps to be
user-configurable by including them in their OEM whitelist file.
This CL respects that and allows these apps to be configured by the user,
despite being granted the permission. If the user rejects the app-op,
PermissionChecker correctly returns false.

Bug: 149742043
Test: atest CrossProfileAppsServiceImplRoboTest
Change-Id: I693338507eec9cdc0ba10a3584e994a58d2d113c