MAGETWO-92697: Add vertical alignment to column configuration

- remove persist attribute from static properties

Author: anthoula

app/code/Magento/PageBuilder/etc/content_type.xsd

@@ -161,7 +161,6 @@
     <xs:complexType name="static_property">
         <xs:attribute type="xs:string" name="source" use="required"/>
         <xs:attribute type="xs:string" name="value" use="optional"/>
-        <xs:attribute type="xs:string" name="persist" use="optional"/>
     </xs:complexType>
     <xs:complexType name="attributes">
         <xs:choice maxOccurs="unbounded">