Renamed the misleading libc/netbsd directory to libc/dns.

Bug: 13219633
Change-Id: Ide43add0b90b3081cc709a22d1ff1f59d65f1104
diff --git a/libc/Android.mk b/libc/Android.mk
index 852db73..f3a2ce8 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -509,7 +509,7 @@
 
 include $(CLEAR_VARS)
 
-LOCAL_SRC_FILES := $(call all-c-files-under,netbsd)
+LOCAL_SRC_FILES := $(call all-c-files-under,dns)
 LOCAL_CFLAGS := \
     $(libc_common_cflags) \
     -DINET6 \