fix(android): Use safeExtGet for compileSdkVersion in expo-handler

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: lucas-zimerman

packages/core/android/expo-handler/build.gradle

@@ -1,11 +1,15 @@
+def safeExtGet(prop, fallback) {
+    rootProject.ext.has(prop) ? rootProject.ext.get(prop) : fallback
+}
+
 apply plugin: 'com.android.library'
 
 android {
-    compileSdkVersion 31
+    compileSdkVersion safeExtGet('compileSdkVersion', 31)
     namespace = "io.sentry.react.expo"
 
     defaultConfig {
-        minSdkVersion 21
+        minSdkVersion safeExtGet('minSdkVersion', 21)
     }
 
     compileOptions {