Issue/12944 unit tests account creation

[JorgeMucientes]

Closes: #12944
⚠️ Do not merge until base branch is trunk

Description

• Adds unit tests to JetpackActivationWPComEmailViewModel
• Removes feature flag to enable account creation during Jetpack flow

Testing information

Checking that unit tests pass should be enough. However, if you want to retest that the account creation flow works well, please follow the steps from this PR: #12935

The tests that have been performed

The above

• I have considered if this change warrants release notes and have added them to RELEASE-NOTES.txt if necessary. Use the "[Internal]" label for non-user-facing changes.

Reviewer (or Author, in the case of optional code reviews):

Please make sure these conditions are met before approving the PR, or request changes if the PR needs improvement:

• The PR is small and has a clear, single focus, or a valid explanation is provided in the description. If needed, please request to split it into smaller PRs.
• Ensure Adequate Unit Test Coverage: The changes are reasonably covered by unit tests or an explanation is provided in the PR description.
• Manual Testing: The author listed all the tests they ran, including smoke tests when needed (e.g., for refactorings). The reviewer confirmed that the PR works as expected on big (tablet) and small (phone) in case of UI changes, and no regressions are added.

129

[wpmobilebot]

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

	App Name	WooCommerce-Wear Android
	Platform	⌚️ Wear OS
	Flavor	Jalapeno
	Build Type	Debug
	Commit	72c49b1
	Direct Download	woocommerce-wear-prototype-build-pr12945-72c49b1.apk

[wpmobilebot]

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

	App Name	WooCommerce Android
	Platform	📱 Mobile
	Flavor	Jalapeno
	Build Type	Debug
	Commit	72c49b1
	Direct Download	woocommerce-prototype-build-pr12945-72c49b1.apk

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 39.76%. Comparing base (af6879f) to head (72c49b1).
Report is 8 commits behind head on trunk.

Additional details and impacted files

@@             Coverage Diff              @@
##              trunk   #12945      +/-   ##
============================================
+ Coverage     39.66%   39.76%   +0.10%     
- Complexity     5955     5961       +6     
============================================
  Files          1262     1262              
  Lines         72942    72940       -2     
  Branches       9977     9976       -1     
============================================
+ Hits          28934    29007      +73     
+ Misses        41437    41356      -81     
- Partials       2571     2577       +6     

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🚨 Try these New Features:

• Flaky Tests Detection - Detect and resolve failed and flaky tests

[hichamboushaba]

Looks good, thanks for taking care of the tests @JorgeMucientes

[dangermattic]

	1 Warning
⚠️	This PR is assigned to the milestone 21.2. This milestone is due in less than 2 days. Please make sure to get it merged by then or assign it to a milestone with a later deadline.

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