enable gradle cache

gradle.properties

@@ -20,4 +20,6 @@ kotlin.code.style=official
 # Enables namespacing of each library's R class so that its R class includes only the
 # resources declared in the library itself and none from the library's dependencies,
 # thereby reducing the size of the R class for that library
-android.nonTransitiveRClass=true
+android.nonTransitiveRClass=true
+# nice optimization
+org.gradle.configuration-cache=true