Issue #2656896: Make product and product variation revisionable

Closes #2656896

modules/product/config/schema/commerce_product.schema.yml

@@ -70,6 +70,9 @@ commerce_product.commerce_product_type.*:
       sequence:
         type: string
         label: 'Variation type'
+    new_revision:
+      type: boolean
+      label: 'Whether a new revision should be created by default'
     multipleVariations:
       type: boolean
       label: 'Allow each product to have multiple variations'