Bump Mixpanel Android SDK to 8.2.4 (from 8.2.0)

[jaya-shankar]

The current build.gradle uses:

implementation 'com.mixpanel.android:mixpanel-android:8.2.0'

However, version 8.2.4 is now available on Maven Central.

Reason for bump:
The current version is outdated and contains a security vulnerability (PR #862) that is causing our app APK to fail security checks. Updating to 8.2.4 will resolve this issue and ensure the app passes security validation.

Request:
Can we please bump the Mixpanel Android SDK version to 8.2.4? 🙏