first commit

core/modules/serialization/config/install/serialization.settings.yml

@@ -0,0 +1,4 @@
+# Before Drupal 8.3, typed data primitive values were normalized as strings, as
+# this was usually returned from database storage. A primitive data normalizer
+# has been introduced to get the casted value instead.
+bc_primitives_as_strings: false

core/modules/serialization/config/schema/serialization.schema.yml

@@ -0,0 +1,7 @@
+serialization.settings:
+  type: config_object
+  label: 'Serialization settings'
+  mapping:
+    bc_primitives_as_strings:
+      type: boolean
+      label: 'Whether to retain pre Drupal 8.3 behavior of serializing all primitive items as strings.'