[device_state] add support for Apps > Special Access > Picture in Picture

Add AppInfoPictureInPictureScreen and AppsPictureInPictureScreen. Add
their keys to the list of settings exposed by the app function. Expose
PictureInPictureDetails function for logic reuse.

Bug: 411491737
Test: adb shell cmd app_function execute-app-function --package com.android.settings   --function getUncategorizedDeviceState --parameters {} | grep --context=5 device_state_app_info_picture_in_picture
Flag: com.android.settings.flags.device_state
Change-Id: I8bc50ce2eb42e31b28463dba4a99447d050fe242