Add sensors for potential and kinetic energy.

PiperOrigin-RevId: 716775375
Change-Id: I012c75686e76af17db0ba97e5b01bd207e1570b1

Author: yuvaltassa

dm_control/mjcf/schema.xml

@@ -2649,6 +2649,30 @@
             <attribute name="body2" type="reference" reference_namespace="body"/>
           </attributes>
         </element>
+        <element name="e_potential" repeated="true" namespace="sensor">
+          <attributes>
+            <attribute name="name" type="identifier"/>
+            <attribute name="noise" type="float"/>
+            <attribute name="user" type="array" array_type="float"/>
+            <attribute name="cutoff" type="float"/>
+          </attributes>
+        </element>
+        <element name="e_kinetic" repeated="true" namespace="sensor">
+          <attributes>
+            <attribute name="name" type="identifier"/>
+            <attribute name="noise" type="float"/>
+            <attribute name="user" type="array" array_type="float"/>
+            <attribute name="cutoff" type="float"/>
+          </attributes>
+        </element>
+        <element name="clock" repeated="true" namespace="sensor">
+          <attributes>
+            <attribute name="name" type="identifier"/>
+            <attribute name="noise" type="float"/>
+            <attribute name="user" type="array" array_type="float"/>
+            <attribute name="cutoff" type="float"/>
+          </attributes>
+        </element>
       </children>
     </element>
     <element name="keyframe">