Update schema pack to 2021.4

Update the script to point to 2021.4.

Tested: built for evb-ast2500, ran Redfish Service Validator:
                             BASE    2021.4
metadataNamespaces:          2330      2388
pass:                        3239      3249
passAction:                     8         8
passGet:                      120       121
passRedfishUri:               114       115
skipNoSchema:                   3         3
skipOptional:                2180      2184
unverifiedAdditional.complex:   2         0
warnDeprecated:               315       315
warningPresent:                12        11
Validation has:         succeeded succeeded

Saw new schemas:
curl -k https://$bmc/redfish/v1/JsonSchemas/Manager/Manager.json
...
    "title": "#Manager.v1_14_0.Manager"
}

Signed-off-by: Sui Chen <suichen@google.com>
Change-Id: I6560ec010362df28e264d80452059b534b3f89ba
diff --git a/static/redfish/v1/schema/VirtualMedia_v1.xml b/static/redfish/v1/schema/VirtualMedia_v1.xml
index e16a3cd..5bd9403 100644
--- a/static/redfish/v1/schema/VirtualMedia_v1.xml
+++ b/static/redfish/v1/schema/VirtualMedia_v1.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!---->
 <!--################################################################################       -->
-<!--# Redfish Schema:  VirtualMedia v1.5.0                                                 -->
+<!--# Redfish Schema:  VirtualMedia v1.5.1                                                 -->
 <!--#                                                                                      -->
 <!--# For a detailed change log, see the README file contained in the DSP8010 bundle,      -->
 <!--# available at http://www.dmtf.org/standards/redfish                                   -->
@@ -469,7 +469,7 @@
         <Property Name="VerifyCertificate" Type="Edm.Boolean">
           <Annotation Term="OData.Permissions" EnumMember="OData.Permission/ReadWrite"/>
           <Annotation Term="OData.Description" String="An indication of whether the service will verify the certificate of the server referenced by the Image property prior to completing the remote media connection."/>
-          <Annotation Term="OData.LongDescription" String="This property shall indicate whether whether the service will verify the certificate of the server referenced by the Image property prior to completing the remote media connection."/>
+          <Annotation Term="OData.LongDescription" String="This property shall indicate whether whether the service will verify the certificate of the server referenced by the Image property prior to completing the remote media connection.  If this property is not supported by the service, it shall be assumed to be `false`.  This property should default to `false` in order to maintain compatibility with older clients."/>
         </Property>
       </EntityType>
     </Schema>
@@ -480,6 +480,12 @@
       <EntityType Name="VirtualMedia" BaseType="VirtualMedia.v1_4_0.VirtualMedia"/>
     </Schema>
 
+    <Schema xmlns="http://docs.oasis-open.org/odata/ns/edm" Namespace="VirtualMedia.v1_4_2">
+      <Annotation Term="Redfish.OwningEntity" String="DMTF"/>
+      <Annotation Term="OData.Description" String="This version was created to clarify the behavior of VerifyCertificate when not supported or configured."/>
+      <EntityType Name="VirtualMedia" BaseType="VirtualMedia.v1_4_1.VirtualMedia"/>
+    </Schema>
+
     <Schema xmlns="http://docs.oasis-open.org/odata/ns/edm" Namespace="VirtualMedia.v1_5_0">
       <Annotation Term="Redfish.OwningEntity" String="DMTF"/>
       <Annotation Term="Redfish.Release" String="2021.2"/>
@@ -494,5 +500,11 @@
       </EntityType>
     </Schema>
 
+    <Schema xmlns="http://docs.oasis-open.org/odata/ns/edm" Namespace="VirtualMedia.v1_5_1">
+      <Annotation Term="Redfish.OwningEntity" String="DMTF"/>
+      <Annotation Term="OData.Description" String="This version was created to clarify the behavior of VerifyCertificate when not supported or configured."/>
+      <EntityType Name="VirtualMedia" BaseType="VirtualMedia.v1_5_0.VirtualMedia"/>
+    </Schema>
+
   </edmx:DataServices>
 </edmx:Edmx>