Update ComposeTesting to Compose 1.2.0 and add new StringHelper methods

[khalp]

📃 Description

Updates dependencies for the ComposeTesting library, including bumping to Compose 1.2.0 and gradle 7.2.0

Also adds new StringHelper methods to use with a ComposeTestRule, as the previous methods only worked with an AndroidComposeTestRule

🤔 Motivation and Context

Keeps SDKs up to date with the latest stable releases

🧪 How Has This Been Tested?

Ran all sample tests on the Surface Duo, and also tested a private artifact with the tests in the TwoPaneLayout library

⚒️ Does the PR contain new tests or refactored old ones?

Both! New tests for the new StringHelper method and to add more examples of test annotations Refactored old tests to fit in with Compose 1.2.0, now with AndroidComposeTestRule there is no need to call setContent

📷 Screenshots (if appropriate)

📦 Types of changes

• [x] New feature (non-breaking change which adds functionality)
• [x] Enhancement to a current functionality
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] Bug fix (non-breaking change which fixes an issue. Please add issue link here too).

✅ Checklist

• [x] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [ ] This PR contains new tests that cover the new code.
• [ ] This PR refactor previous tests to cover the new code.
• [ ] This PR is part of a set of PRs that build a bigger feature. If so, please, add here links to previously merged or open PRs.