Fix advanced-rebootpy datetime EDecimal type issue.

[ryanzhu706]

issue seen on 2700 https://dev.azure.com/mssonic/internal/_build/results?buildId=913225&view=logs&j=76acabad-01e9-5c52-6fe6-d396d63e85d2&t=55864d99-7fe9-5504-0078-bfbb010fc228&l=4109

2025-08-01T12:37:49.4730701Z 2025-08-01 12:37:43 : --------------------------------------------------
2025-08-01T12:37:49.4731666Z 2025-08-01 12:37:43 : Fails:
2025-08-01T12:37:49.4732373Z 2025-08-01 12:37:43 : --------------------------------------------------
2025-08-01T12:37:49.4733177Z 2025-08-01 12:37:43 : FAILED:dut:Traceback (most recent call last):
2025-08-01T12:37:49.4733944Z   File "/root/ptftests/py3/advanced-reboot.py", line 1445, in runTest
2025-08-01T12:37:49.4734679Z     self.handle_advanced_reboot_health_check()
2025-08-01T12:37:49.4735464Z   File "/root/ptftests/py3/advanced-reboot.py", line 1167, in handle_advanced_reboot_health_check
2025-08-01T12:37:49.4736205Z     self.examine_flow()
2025-08-01T12:37:49.4736865Z   File "/root/ptftests/py3/advanced-reboot.py", line 2138, in examine_flow
2025-08-01T12:37:49.4737694Z     self.disruption_stop = datetime.datetime.fromtimestamp(
2025-08-01T12:37:49.4738332Z                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2025-08-01T12:37:49.4739025Z TypeError: 'EDecimal' object cannot be interpreted as an integer
2025-08-01T12:37:49.4739366Z
2025-08-01T12:37:49.4740035Z 2025-08-01 12:37:43 : ==================================================
2025-08-01T12:37:49.4740823Z 2025-08-01 12:37:43 : Disabling arp_responder
2025-08-01T12:37:49.4741111Z

Description of PR

Summary:
Fixes # (issue)

Type of change

• Bug fix
• Testbed and Framework(new/improvement)
• New Test case
  • Skipped for non-supported platforms
• Test case improvement

Back port request

• 202205
• 202305
• 202311
• 202405
• 202411
• 202505

Approach

What is the motivation for this PR?

Issue seen in 2700/7260 202411 upgrade pipelines.

How did you do it?

How did you verify/test it?

https://dev.azure.com/mssonic/internal/_build/results?buildId=915470&view=results

Any platform specific information?

Supported testbed topology if it's a new test case?

Documentation

[mssonicbld]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[ryanzhu706]

Hi @yxieca or @StormLiangMS, could you help please merge and cherry pick? Thanks!

[StormLiangMS]

LGTM

[mssonicbld]

Cherry-pick PR to 202411: #20131

[mssonicbld]

Cherry-pick PR to 202405: #20132

[mssonicbld]

Cherry-pick PR to 202311: #20133

[mssonicbld]

Cherry-pick PR to 202505: #20139