gNMI support extended for JTI

Junos telemetry interface (JTI) sensor support extends the ability to configure the following resource paths that use gRPC for export to also use gRPC Management Interface (gNMI) for export. gNMI is a protocol for configuration and retrieval of state information.
JTI supports the following resource paths:

• /components/component/properties/property/state/value
• /components/component/state/
• /interfaces/interface/state/
• /interfaces/interface/subinterfaces/subinterface/state/

To provision the sensor to export data through gNMI, use the Subscribe RPC defined in the gnmi.proto to specify request parameters. Streaming telemetry data through gNMI also requires the OpenConfig for Junos OS module. 

OpenConfig and Network Agent packages are bundled into the Junos OS image by default. Both packages support the JTI.