Update to AndroidX Core 1.15.0

[MGaetan89]

Pull request

Description

In #781, we received an update for AndroidX Core to use version 1.15.0. This version requires compile SDK to be 35 or newer.
This PR performs the update and performs the necessary code changes.

Changes made

• Update to AndroidX Core 1.15.0.
• Bump the compile SDK version to 35.
• Fix retrieval of the app version name for ComScore. That field can be null now, in which case we use an empty string.
• Fix some code documentation.
• Remove deprecated code in pillarbox-demo-cast. This is no longer necessary since Enable edge-to-edge in the demo application #658.

Checklist

• APIs have been properly documented (if relevant).
• The documentation has been updated (if relevant).
• New unit tests have been written (if relevant).
• The demo has been updated (if relevant).

[github-actions]

Code Coverage

Overall Project	47.8%	🟢
Files changed	100%	🟢

Module	Coverage
:pillarbox-analytics	88.04%	🟢
Kover Gradle Plugin XML report for :plugins	7.46%	🟢

Files

Module	File	Coverage
:pillarbox-analytics	ComScoreSrg.kt	90.5%	🟢
Kover Gradle Plugin XML report for :plugins	AppConfig.kt	0%	🟢