[action] [PR:16355] [Nokia-IXR7250E] Modify the platform_ndk.json for Nokia-IXR7250E platform

[mssonicbld]

Why I did it

On Nokia IXR7250E platform, per latest requirement, linecard no longer to reboot itself when midplane heartbeat is missing.
This PR address issue https://github.com/Nokia-ION/ndk/issues/20

Work item tracking

• Microsoft ADO (number only): 25036266

How I did it

Modify the platform_ndk.json file and change the value of "monitor_action" from "reboot" to "warn" to let Linecard's NDK to log the Error message instead of reboot itself.

How to verify it

1. Log in supervisor card, issue the following command to bring down the midplane communication.

 sonic#> sudo ethtool -s xe0 autoneg on

2. On the linecard console, wait for 1 minute or more. The following log message should be shown up. And No reboot action happened.

Aug 31 02:46:59.786135 ixre-egl-board25 WARNING sr_device_mgr: Unable to reach CPM over 10.6.0.100 (missing count: 6).

Which release branch to backport (provide reason below if selected)

• 201811
• 201911
• 202006
• 202012
• 202106
• 202111
• 202205
• 202211
• 202305

Tested branch (Please provide the tested image version)

Description for the changelog

Link to config_db schema for YANG module changes

A picture of a cute animal (not mandatory but encouraged)

[mssonicbld]

Original PR: #16355