Update UnifiedAboutActivity.kt

[OneBitSailor]

Fixed lifecycle and possible injection issues in UnifiedAboutActivity along side with implementing safe check for possible invalid URLs or missing external web browsers.

Description

• Safe Dependency Injection: Ensured Dagger injection occurs before super.onCreate to prevent lifecycle race conditions where the framework might try to restore state or fragments using fields before they are injected.

• Safe URL Interaction: Encapsulated the external URL launcher in a explicit try-catch block capturing ActivityNotFoundException. This guarantees the app will not crash on low-end or highly restricted devices lacking a default web browser or when processed an invalid deep-link structure.

Testing instructions

Test Case 1: Standard navigation and external link launching

1. Clicking upon blog button in about.
2. The link will be redirected to URLs upon action.

• Verify that the external web browser opens immediately to the correct URL.

3. Rotate the device while the browser is open or right after returning to the app.

• Verify that the app does not repeatedly attempt to launch the browser or crash due to configuration changes.

Test Case 2: Error handling on missing browser or invalid URL

1. (Optional/Simulated) Use a device/emulator with no default web browser installed, or temporarily disable your system browser.
2. Trigger the action that calls openExternalBlogUrl with an invalid link schema or restricted destination.

• Verify that the app does not crash.
• Verify that a Toast message appears displaying "Invalid URL or external activity!".
  Use numbered lists for action steps and checkboxes for verifications.
  Organise by test case title when there are multiple scenarios.

Self-Testing Checklist

• Compatibility with WordPress.com sites and self-hosted Jetpack sites: Verified that the UnifiedAboutActivity correctly resolves config settings provided by the UnifiedAboutViewModel regardless of whether the active authenticated user profile belongs to a WordPress.com account or a self-hosted Jetpack site.