Explicitly set the conformance.

Author: hicklin

src/app/zap-templates/zcl/data-model/chip/global-structs.xml

@@ -18,6 +18,7 @@ limitations under the License.
 <!--
 TODO: Make these structures global rather than defining them for each cluster.
  This depends on the ability to define global structs via XML tags.
+ see: https://github.com/project-chip/connectedhomeip/issues/29818
 -->
 
 <configurator>
@@ -26,8 +27,8 @@ TODO: Make these structures global rather than defining them for each cluster.
     <cluster code="0x0150"/> <!-- Service Area Cluster -->
     <!-- TODO: add Basic Information Cluster code="0x0028" -->
 
-    <item fieldId="0" name="LocationName"    type="char_string" length="128" isNullable="false"/>
-    <item fieldId="1" name="FloorNumber"     type="int16s"                   isNullable="true"/>
-    <item fieldId="2" name="AreaType"        type="AreaTypeTag"              isNullable="true"/>
+    <item fieldId="0" name="LocationName"    type="char_string" length="128" isNullable="false" optional="false"/>
+    <item fieldId="1" name="FloorNumber"     type="int16s"                   isNullable="true"  optional="false"/>
+    <item fieldId="2" name="AreaType"        type="AreaTypeTag"              isNullable="true"  optional="false"/>
   </struct>
 </configurator>