If the step index saved in the instance state is invalid reset the wizard

[antonis]

Fixes #19758

Description

Under undefined conditions the Site Creation flow is resumed with an invalid step retrieved from the saved instance state. This results in a crash due to an unhandled exception thrown in the step validation. This PR adds exception handling and resets the site creation flow in this edge case.

IllegalStateException: Invalid index.
    at org.wordpress.android.util.wizard.WizardManager.setCurrentStepIndex(WizardManager.kt:52)
    at org.wordpress.android.ui.sitecreation.SiteCreationMainVM.start(SiteCreationMainVM.kt:172)
    at org.wordpress.android.ui.sitecreation.SiteCreationActivity.onCreate(SiteCreationActivity.kt:11

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To Test:

• I wasn't able to reproduce the crash thus a sanity check on the flow is recommended.

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Regression Notes

1. Potential unintended areas of impact

Site Creation

2. What I did to test those areas of impact (or what existing automated tests I relied on)

Manual testing

3. What automated tests I added (or what prevented me from doing so)

New test with in the SiteCreationMainVMTest.kt

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PR Submission Checklist:

• I have completed the Regression Notes.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

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UI Changes Testing Checklist:

• Portrait and landscape orientations.
• Light and dark modes.
• Fonts: Larger, smaller and bold text.
• High contrast.
• Talkback.
• Languages with large words or with letters/accents not frequently used in English.
• Right-to-left languages. (Even if translation isn’t complete, formatting should still respect the right-to-left layout)
• Large and small screen sizes. (Tablet and smaller phones)
• Multi-tasking: Split screen and Pop-up view. (Android 10 or higher)

[wpmobilebot]

📲 You can test the changes from this Pull Request in Jetpack by scanning the QR code below to install the corresponding build.

	App Name	Jetpack
	Flavor	Jalapeno
	Build Type	Debug
	Version	pr19760-bf6fe27
	Commit	bf6fe27
	Direct Download	jetpack-prototype-build-pr19760-bf6fe27.apk

Note: Google Login is not supported on these builds.

[wpmobilebot]

📲 You can test the changes from this Pull Request in WordPress by scanning the QR code below to install the corresponding build.

	App Name	WordPress
	Flavor	Jalapeno
	Build Type	Debug
	Version	pr19760-bf6fe27
	Commit	bf6fe27
	Direct Download	wordpress-prototype-build-pr19760-bf6fe27.apk

Note: Google Login is not supported on these builds.

[justtwago]

Thank you for the fix and the test for it! Looks good to me! 👍