IOS XR get_bgp_neighbors_detail: flap_count return a negative value

Description of Issue/Question

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I notice that the get_bgp_neighbors_detail function returns a negative value for flap_count as seen in the output below.
Script
=====
from napalm import get_network_driver
driver = get_network_driver('iosxr')
device1.open()

info = device1.get_bgp_neighbors_detail()
print (json.dumps(info, indent=4))

Output returned:
===========
    "VRF-A": {
        "110": [
            {
                "up": true,
                "local_as": 18522,
                "remote_as": 110,
                "router_id": "198.0.0.177",
                "local_address": "10:11:b0::1",
                "routing_table": "VRF-A",
                "local_address_configured": false,
                "local_port": 179,
                "remote_address": "10:11:b0::11",
                "remote_port": 33155,
                "multihop": false,
                "multipath": false,
                "import_policy": "pass-all",
                "export_policy": "pass-all",
                "input_messages": 0,
                "output_messages": 3061,
                "input_updates": 0,
                "output_updates": 0,
                "messages_queued_out": 0,
                "connection_state": "Established",
                "previous_connection_state": "Connect",
                "last_event": "",
                "remove_private_as": false,
                "suppress_4byte_as": false,
                "local_as_prepend": true,
                "holdtime": 90,
                "configured_holdtime": 180,
                "keepalive": 30,
                "configured_keepalive": 60,
                "active_prefix_count": 101,
                "received_prefix_count": 101,
                "accepted_prefix_count": 101,
                "suppressed_prefix_count": 0,
                "advertised_prefix_count": 202,
                **"flap_count": -1**
            }
        ]
    }

I looked at the following relevant code at napalm/napalm/iosxr/iosxr.py:

                connection_down_count = napalm.base.helpers.convert(
                    int,
                    napalm.base.helpers.find_txt(neighbor, "ConnectionDownCount"),
                    0,
                )

               flap_count = int(connection_down_count / 2)
                if up:
                    **flap_count -= 1**

The connection-down-count field can have value in the range 0 to 4294967295. If the value is 0, the above code will result in a flap_count that is negative. This logic needs to be fixed.

Did you follow the steps from https://github.com/napalm-automation/napalm#faq

(Place an x between the square brackets where applicable)

[x] Yes
[] No

Setup

napalm version

(Paste verbatim output from pip freeze | grep napalm between quotes below)

napalm==3.2.0
napalm-yang==0.1.0

Network operating system version

(Paste verbatim output from show version - or equivalent - between quotes below)

Cisco IOS XR Software, Version 7.4.1.08I

Steps to Reproduce the Issue

Error Traceback

(Paste the complete traceback of the exception between quotes below)

napalm-automation / napalm

IOS XR get_bgp_neighbors_detail: flap_count return a negative value #1330