fix: remove conditional expressions for compileSdkVersion and targetSdkVersion

- Simplify specifying compileSdkVersion and targetSdkVersion directly from flutter configuration

Author: muzahidul-opti

example/android/app/build.gradle

@@ -26,9 +26,7 @@ if (flutterVersionName == null) {
 android {
     namespace "com.optimizely.optimizely_flutter_sdk_example"
 
-    compileSdkVersion rootProject.hasProperty('flutter.compileSdkVersion') 
-                        ? rootProject.flutter.compileSdkVersion.toInteger() 
-                        : 35
+    compileSdkVersion flutter.compileSdkVersion
 
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_8
@@ -41,9 +39,7 @@ android {
         // You can update the following values to match your application needs. 
         // For more information, see: https://docs.flutter.dev/deployment/android#reviewing-the-build-configuration.
         minSdkVersion flutter.minSdkVersion
-        targetSdkVersion rootProject.hasProperty('flutter.targetSdkVersion') 
-                        ? rootProject.flutter.targetSdkVersion.toInteger() 
-                        : 35
+        targetSdkVersion flutter.targetSdkVersion
 
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName