Reduce DB queries for looking up transport properties.

...arproject/bramble/plugin/droidtooth/DroidtoothPlugin.java

...n/java/org/briarproject/bramble/plugin/tor/TorPlugin.java

...a/org/briarproject/bramble/api/plugin/PluginCallback.java

...ject/bramble/api/properties/TransportPropertyManager.java

...va/org/briarproject/bramble/plugin/PluginManagerImpl.java

...n/java/org/briarproject/bramble/plugin/tcp/TcpPlugin.java

...ject/bramble/properties/TransportPropertyManagerImpl.java

...org/briarproject/bramble/plugin/tcp/LanTcpPluginTest.java

...riarproject/bramble/plugin/bluetooth/BluetoothPlugin.java

...va/org/briarproject/bramble/plugin/modem/ModemPlugin.java

...rg/briarproject/bramble/plugin/modem/ModemPluginTest.java