Implement subscribe poll for the devicesim

[adibrastegarnia]

1- The devsim supports subscribe poll as well.
2- Porting the gnmi server code to the repo that we add the new features that we need.

[SeanCondon]

When I ran this - it gives the POLL response every 5 seconds showing Dublin, but when went and changed the TZ value in another terminal to Paris, the POLL event continued giving the old Dublin value. I'd expect it to start transmitting the updated value. Even after restarting the POLL it still displays the old value "Dublin"

[adibrastegarnia]

When I ran this - it gives the POLL response every 5 seconds showing Dublin, but when went and changed the TZ value in another terminal to Paris, the POLL event continued giving the old Dublin value. I'd expect it to start transmitting the updated value. Even after restarting the POLL it still displays the old value "Dublin"

Thanks for catching the error. I will take a look to see what is going on.

[adibrastegarnia]

When I ran this - it gives the POLL response every 5 seconds showing Dublin, but when went and changed the TZ value in another terminal to Paris, the POLL event continued giving the old Dublin value. I'd expect it to start transmitting the updated value. Even after restarting the POLL it still displays the old value "Dublin"

@SeanCondon

I addressed your comment and I think this part is ready to merge. Whenever you get a chance, please test it and see will you get the expected output for subscribe poll and once. Thanks

[SeanCondon]

This gives me a

# _/home/devicesim/gnmi_target
./gnmi_utils.go:115:1: syntax error: non-declaration statement outside function body