Add ::1 to localhost in etc/hosts

::1 is IPv6 loopback address.

Bug: 256507503
Test: $ adb shell /data/dnschk localhost
      # localhost (via nethandle 0):
      127.0.0.1
      ::1
Change-Id: Ibcee52a14143856db50fca301c48ea9e2591914b
diff --git a/rootdir/etc/hosts b/rootdir/etc/hosts
index 649151c..2e506a8 100644
--- a/rootdir/etc/hosts
+++ b/rootdir/etc/hosts
@@ -1,2 +1,2 @@
 127.0.0.1       localhost
-::1             ip6-localhost
+::1             localhost ip6-localhost