Bugzilla

### Beta/Release Uplift Approval Request
* **User impact if declined**: The title string of some Feature Callout messages (such as those in Firefox View and an upcoming PDF.js experiment) will be truncated for users in some locales.
* **Is this code covered by automated tests?**: No
* **Has the fix been verified in Nightly?**: No
* **Needs manual test from QE?**: Yes
* **If yes, steps to reproduce**: [Prerequisites]:

    - Firefox with "fr" locale installed.
    - Have a new Firefox profile with the "nimbus.debug" pref set to "true" in the "about:config" page.

[ Steps ]:

    - Open the browser with the profile from the prerequisites.
    - Navigate to about:studies?optin_slug=pdfjs-feature-callout&optin_branch=treatment-b&optin_collection=nimbus-preview.
    - Navigate to an URL ending in ".pdf" (e.g. https://www.africau.edu/images/default/sample.pdf).
    - Observe the PDF callout message.

[Expected result]:

    All the elements from the PDF callout message are visible and the title text is not truncated.
* **List of other uplifts needed**: None
* **Risk to taking this patch**: Low
* **Why is the change risky/not risky? (and alternatives if risky)**: This is a small CSS change that is scoped to this specific messaging surface. The change has been approved by representatives from design and UX.
* **String changes made/needed**: n/a
* **Is Android affected?**: No

### Beta/Release Uplift Approval Request
* **User impact if declined**: The title string of some Feature Callout messages (such as those in Firefox View and an upcoming PDF.js experiment) will be truncated for users in some locales.
* **Is this code covered by automated tests?**: No
* **Has the fix been verified in Nightly?**: No
* **Needs manual test from QE?**: Yes
* **If yes, steps to reproduce**: 

[Prerequisites]:
    - Firefox with "fr" locale installed.
    - Have a new Firefox profile with the "nimbus.debug" pref set to "true" in the "about:config" page.

[ Steps ]:
    - Open the browser with the profile from the prerequisites.
    - Navigate to about:studies?optin_slug=pdfjs-feature-callout&optin_branch=treatment-b&optin_collection=nimbus-preview.
    - Navigate to an URL ending in ".pdf" (e.g. https://www.africau.edu/images/default/sample.pdf).
    - Observe the PDF callout message.

[Expected result]:
    All the elements from the PDF callout message are visible and the title text is not truncated.
* **List of other uplifts needed**: None
* **Risk to taking this patch**: Low
* **Why is the change risky/not risky? (and alternatives if risky)**: This is a small CSS change that is scoped to this specific messaging surface. The change has been approved by representatives from design and UX.
* **String changes made/needed**: n/a
* **Is Android affected?**: No