Refactor code

Author: DenysZP

app/build.gradle

@@ -33,9 +33,11 @@ android {
         }
         shopifyApi {
             dimension "api"
+
             def shopappShopifyVersion = project.getProperties().get("shopappShopifyVersion")
-            shopappShopifyVersion = shopappShopifyVersion != null ? shopappShopifyVersion : "1.0.2"
-            apiLibrary = "com.github.rubygarage:shopapp-shopify-android:$shopappShopifyVersion"
+            if (shopappShopifyVersion != null) {
+                apiLibrary = "com.github.rubygarage:shopapp-shopify-android:$shopappShopifyVersion"
+            }
 
             def appId = project.getProperties().get("appId")
             applicationId = appId != null ? appId : applicationId