Migrate to using = for property setting

Gradle has deprecated `compileSdk 35` style syntax in
Gradle 8.12, in preparation for that upgrade, fix up the violations
in androidx build.gradle files

Test: ./gradlew bOS --dry-run -> https://ge.androidx.dev/s/bqs4fmehxdqzs/deprecations
      and after -> https://ge.androidx.dev/s/nvc7s5bdfpuaa/deprecations
Change-Id: Ic4787d46f40e3856e5f0fa1e3c0a63e3dddc2108
diff --git a/appsearch/appsearch-ktx/build.gradle b/appsearch/appsearch-ktx/build.gradle
index 5be9af0..5dedd3e 100644
--- a/appsearch/appsearch-ktx/build.gradle
+++ b/appsearch/appsearch-ktx/build.gradle
@@ -50,6 +50,6 @@
 }
 
 android {
-    compileSdk 35
-    namespace "androidx.appsearch.ktx"
+    compileSdk = 35
+    namespace = "androidx.appsearch.ktx"
 }