chore: update compile/targetSdk to 35 (Android 15)

[maureenorea-clores]

Description

• Change compile/targeSdk of sample app to 35 (Android 15)
• Bump AGP to 8+
• Use updated android-buildconfig which supports AGP 8+
• Fix gradlew assemble error related to proguard

Links

N/A

Checklist

• I have read the contributing guidelines.
• I wrote/updated tests for new/changed code
• I removed all sensitive data before every commit, including API endpoints and keys, and internal links
• I checked that all possible internal and platform/library exceptions are gracefully handled and will not crash the host app
• I checked for open & known issues (especially crashes) for any newly added platform APIs or libraries
• I tested non-trivial changes on a real device
• I added ticket/changes in changelog
• I ran ./gradlew check without errors

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud