Add a disable flag for sensors.

PiperOrigin-RevId: 469473066
Change-Id: I0a6e4370f93d47033630a86be988804062b6c273

Author: yuvaltassa

dm_control/mjcf/schema.xml

@@ -81,6 +81,7 @@
             <attribute name="filterparent" type="keyword" valid_values="disable enable"/>
             <attribute name="actuation" type="keyword" valid_values="disable enable"/>
             <attribute name="refsafe" type="keyword" valid_values="disable enable"/>
+            <attribute name="sensor" type="keyword" valid_values="disable enable"/>
             <attribute name="override" type="keyword" valid_values="disable enable"/>
             <attribute name="energy" type="keyword" valid_values="disable enable"/>
             <attribute name="fwdinv" type="keyword" valid_values="disable enable"/>