fix(package_info_plus): incorrect install time returned on macOS when app sandbox disabled

[MortyFx]

Description

Currently, this plugin get the installTime by retrieving the creation date of NSDocumentDirectory on macOS. However, the path of NSDocumentDirectory varies on whether the app has the app sandbox enabled.

NSDocumentDirectory path return value when App Sandbox:

• Enabled: ~/Library/Containers/<BundleId>/Data/Documents
• Disabled: ~/Documents

This is leading to 2 problems when App Sandbox Disabled:

1. The creation date of ~/Documents can't be used as app first installation time.
2. Triggering a confirmation dialog that informs the user the app wants to access files in the User Documents folder — even though the app may not have intended to do so. See:
   

This PR fixes the issue by returning the main bundle's last modified date as the installTime when the app is not sandboxed. Since currently there's no reliable way to get the first install time when sandbox disabled, the modified date is used as an approximate fallback.

Related Issues

Fixes #3636, #3434 (comment)

Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I titled the PR using Conventional Commits.
• I did not modify the CHANGELOG.md nor the plugin version in pubspec.yaml files.
• All existing and new tests are passing.
• The analyzer (flutter analyze) does not report any problems on my PR.

Breaking Change

Does your PR require plugin users to manually update their apps to accommodate your change?

• Yes, this is a breaking change (please indicate that with a ! in the title as explained in Conventional Commits).
• No, this is not a breaking change.

[vbuberen]

Thank you for detailed report and for fixing the issue.
I will release this fix somewhere during next few days