From https://cs.chromium.org/chromium/src/device/bluetooth/bluetooth_gatt_characteristic.h?rcl=0&l=66
Currently BlueZ infers permissions for characteristics from the properties. Once this is fixed, we will start sending the permissions for characteristics to BlueZ. Till then permissions for characteristics are unimplemented.

Once this is fixed, the internals page needs to use the permissions property instead of the properties property of DeviceInfo to check permissions.