[CLATJ#26] ClatCoordinator: reword clatd starting failure logging

Bug: 212345928
Test: build
Change-Id: Ie826477d27db26cc49d113ec8bfacaaa3006e26e

tests/unit/java/com/android/server/connectivity/ClatCoordinatorTest.java

@@ -340,7 +340,7 @@ public class ClatCoordinatorTest {
         inOrder.verifyNoMoreInteractions();
 
         // [2] Start clatd again failed.
-        assertThrows("java.io.IOException: Clatd has started on test0 (pid 10483)",
+        assertThrows("java.io.IOException: Clatd is already running on test0 (pid 10483)",
                 IOException.class,
                 () -> coordinator.clatStart(BASE_IFACE, NETID, NAT64_IP_PREFIX));