fix(android): downgrade AGP to 8.9.1 for Android Studio compatibility

- Change Android Gradle Plugin from 8.10.1 to 8.9.1
- Resolves compatibility issue with Android Studio
- Maintains compatibility with Gradle 8.11.1 wrapper

Author: Matthew Raymer

SECURITY AUDIT CHECKLIST:
- [x] No security implications from AGP version change
- [x] Version downgrade is to stable, supported version
- [x] Build process remains secure and functional

android/build.gradle

@@ -7,7 +7,7 @@ buildscript {
         mavenCentral()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:8.10.1'
+        classpath 'com.android.tools.build:gradle:8.9.1'
         classpath 'com.google.gms:google-services:4.4.0'
 
         // NOTE: Do not place your application dependencies here; they belong