Peripheral is still connected after app closed

[yanshouwang]

I have written a plugin with bluez to support Linux platform, but I found two issues after test.
The first issue is peripheral is still connected after I closed the app, this is not an expected behavior on the other platforms.
The second issue is The bluez objects, such as bluezAdapter, bluezCharacteristic, etc, is not override the hashCode and the equals method, this cause the same adapter, characteristic or other objects can't equals although they have same address or uuid，and also there will have characteristics with the same uuid but in different services, so we can't use uuid easily to judge whether two characteristics are the same instance