LightWalletGrpcService(appContext: Context, host: String, port: Int = DEFAULT_LIGHTWALLETD_PORT, usePlaintext: Boolean = appContext.resources.getBoolean(R.bool.lightwalletd_allow_very_insecure_connections))
Construct an instance that corresponds to the given host and port.
appContext - the application context used to check whether TLS is required by this build
flavor.
host - the host of the server to use.
port - the port of the server to use.
usePlaintext - whether to use TLS or plaintext for requests. Plaintext is dangerous so
it requires jumping through a few more hoops.