Improve the nduser option log readability.

Before:
Nduseroptmsg(10, 40, 48, 134, 0, fe80::2a00:79e1:abc:f605%wlan0)

after:
Nduseroptmsg(family:10, opts_len:40, ifindex:48, icmp_type:134, icmp_code:0, srcaddr: fe80::2a00:79e1:abc:f605%wlan1, NdOptRdnss(type: 25, length: 5, reserved: 0, lifetime: 1209600,servers:[2001:4860:4860::6464,2001:4860:4860::64]))

Bug: 315069348
Test: TH
Change-Id: I3abfbecd53a8cc00eaed9cbac1d9fe187d265847
diff --git a/staticlibs/device/com/android/net/module/util/netlink/NduseroptMessage.java b/staticlibs/device/com/android/net/module/util/netlink/NduseroptMessage.java
index 2e9a99b..586f19d 100644
--- a/staticlibs/device/com/android/net/module/util/netlink/NduseroptMessage.java
+++ b/staticlibs/device/com/android/net/module/util/netlink/NduseroptMessage.java
@@ -156,8 +156,9 @@
 
     @Override
     public String toString() {
-        return String.format("Nduseroptmsg(%d, %d, %d, %d, %d, %s)",
+        return String.format("Nduseroptmsg(family:%d, opts_len:%d, ifindex:%d, icmp_type:%d, "
+                + "icmp_code:%d, srcaddr: %s, %s)",
                 family, opts_len, ifindex, Byte.toUnsignedInt(icmp_type),
-                Byte.toUnsignedInt(icmp_code), srcaddr.getHostAddress());
+                Byte.toUnsignedInt(icmp_code), srcaddr.getHostAddress(), option);
     }
 }
diff --git a/staticlibs/tests/unit/src/com/android/net/module/util/netlink/NduseroptMessageTest.java b/staticlibs/tests/unit/src/com/android/net/module/util/netlink/NduseroptMessageTest.java
index 4fc5ec2..d1df3a6 100644
--- a/staticlibs/tests/unit/src/com/android/net/module/util/netlink/NduseroptMessageTest.java
+++ b/staticlibs/tests/unit/src/com/android/net/module/util/netlink/NduseroptMessageTest.java
@@ -252,8 +252,10 @@
     public void testToString() {
         NduseroptMessage msg = parseNduseroptMessage(toBuffer(MSG_PREF64));
         assertNotNull(msg);
-        assertEquals("Nduseroptmsg(10, 16, 1431655765, 134, 0, fe80:2:3:4:5:6:7:8%1431655765)",
-                msg.toString());
+        final String expected = "Nduseroptmsg(family:10, opts_len:16, ifindex:1431655765, "
+                + "icmp_type:134, icmp_code:0, srcaddr: fe80:2:3:4:5:6:7:8%1431655765, "
+                + "NdOptPref64(2001:db8:3:4:5:6::/96, 10064))";
+        assertEquals(expected, msg.toString());
     }
 
     // Convenience method to parse a NduseroptMessage that's not part of a netlink message.