Wait for disconnection to remove properties of temporarily paired device

BT stack always generate BOND_NONE bond state change on completing
temporary pairing. This event ends up removing the device properties for
devices connected using insecure connections.
This fix will now wait for the devices to be disconnected to remove the
device properties when bond was not outright removed.

Test: mmm packages/modules/Bluetooth
Test: Manual | CtsVerifier app > Bluetooth Test > Insecure Client and Insecure
Flag: com.android.bluetooth.flags.temporary_pairing_device_properties
Bug: 341196265
Bug: 342202557
Change-Id: I1ece44dd68ce2a1db841984d827b7b131e53f94f