Onboard azure-sphere-tools pipelines to Network Isolation policy

[Copilot]

Context

This PR onboards the azure-sphere-tools pipeline to the Network Isolation policy (SFI ES4.2.4) and fixes flaky ClearErrorReportData tests.

This is part of a two-PR change to onboard azure-sphere-tools to network isolation:

1. SdkBuildScripts PR — must be completed first
2. This PR (azure-sphere-tools) — complete after SdkBuildScripts merges, then revert the temporary ref: changes below

Changes in this PR

Network Isolation

• build.yml: Added networkisolation feature flag with Permissive,CFSClean,CFSClean2,CFSClean3 policy to the non-official OneBranch template.
• build-release.yml: Added the same networkisolation feature flag to the official OneBranch template.
• build.yml: Temporary ref: changes to point SdkBuildScripts and azure-sphere-tools resources at feature branches (marked with # TODO comments — revert to refs/heads/main after both PRs merge).

Test Fixes

• ClearErrorReportDataTests.cs: Fixed Assert.AreEqual argument order (expected, actual were swapped). Increased poll timeout from 1s to 5s. Added retry logic (up to 3 attempts) to handle intermittent device delays when clearing error report data.
• test_clear_error_report_data.py: Same fixes — increased timeout from 1s to 5s and added retry logic (up to 3 attempts).

Validation

• Automated on-device testing (both .NET and Python tests pass)

[glcardoz]

@copilot also onboard to CFSClean3

[Copilot]

@copilot also onboard to CFSClean3

Done — updated both build.yml and build-release.yml to include CFSClean3 in the policy (commit d30f624).