Fix device handling in restricted mode

Security policy regarding guest mode:
1. Guest user is not allowed to remove devices added by the regular users.
>> Worked fine
2. Guest users are allowed to remove only the devices added in guest mode.
>> Did not work
3. Also the devices added in guest mode are autonomously removed on exiting the guest mode.
>> Did not work for LE-only devices.

Bug: 288069181
Change-Id: Ia9bd8219961ff110d053cdd9a810dc6c55b674f6
Test: atest BluetoothInstrumentationTests
Test: Pair/unpair devices in guest mode