NetlinkEvent - ignore captive portal and pref64 nd user opts

These are provided to userspace by newer kernels.

Test: builds
Bug: 150648313
Change-Id: I811c75e9a4739db149f502b9a43c99a8ed883341
diff --git a/libsysutils/src/NetlinkEvent.cpp b/libsysutils/src/NetlinkEvent.cpp
index 2351afa..5efe03f 100644
--- a/libsysutils/src/NetlinkEvent.cpp
+++ b/libsysutils/src/NetlinkEvent.cpp
@@ -529,6 +529,10 @@
         free(buf);
     } else if (opthdr->nd_opt_type == ND_OPT_DNSSL) {
         // TODO: support DNSSL.
+    } else if (opthdr->nd_opt_type == ND_OPT_CAPTIVE_PORTAL) {
+        // TODO: support CAPTIVE PORTAL.
+    } else if (opthdr->nd_opt_type == ND_OPT_PREF64) {
+        // TODO: support PREF64.
     } else {
         SLOGD("Unknown ND option type %d\n", opthdr->nd_opt_type);
         return false;