LinuxTorPlugin: Address review comments

.../briarproject/bramble/system/AndroidResourceProvider.java

...org/briarproject/bramble/api/system/ResourceProvider.java

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

bramble-j2se/build.gradle

...va/org/briarproject/bramble/api/ConfigurationManager.java

.../org/briarproject/bramble/network/JavaNetworkManager.java

...a/org/briarproject/bramble/plugin/tor/LinuxTorPlugin.java

...riarproject/bramble/plugin/tor/LinuxTorPluginFactory.java

...org/briarproject/bramble/system/JavaResourceProvider.java

bramble-j2se/witness.gradle