Updated internal Rollbar SDK to 3.2.0

[matux]

Description of the change

This PR updates the internal Rollbar SDK to 3.2.0, this will allow us to drop the minimum Apple OS requirement of our Flutter SDK to the minimum supported by Apple.

This PR also updates the changelog and SDK version to 1.5.0, making it ready for publish.

Type of change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Maintenance
• New release

Checklists

Development

• Lint rules pass locally
• The code changed/added as part of this pull request has been covered with tests
• All tests related to the changed code pass in development

Code review

• This pull request has a descriptive title and information useful to a reviewer. There may be a screenshot or screencast attached
• "Ready for review" label attached to the PR and reviewers assigned
• Issue from task tracker has a link to this pull request
• Changes have been reviewed by at least one other engineer