HADOOP-17245. Add OzoneFileSystem classes to core-default.xml. (#2276)

hadoop-common-project/hadoop-common/src/main/resources/core-default.xml

@@ -3979,4 +3979,18 @@
       ThreadGroup approach is preferred for better performance.
     </description>
   </property>
+
+  <property>
+    <name>fs.AbstractFileSystem.ofs.impl</name>
+    <value>org.apache.hadoop.fs.ozone.RootedOzFs</value>
+    <description>The AbstractFileSystem for Rooted Ozone
+      FileSystem ofs uri</description>
+  </property>
+
+  <property>
+    <name>fs.AbstractFileSystem.o3fs.impl</name>
+    <value>org.apache.hadoop.fs.ozone.OzFs</value>
+    <description>The AbstractFileSystem for Ozone FileSystem o3fs uri</description>
+  </property>
+
 </configuration>