authfs/fd_server: set prefer_rlib to true

Bug: 188195485
Test: linker64 --list authfs/fd_server  # doesn't see rlib

Change-Id: I159de4cc2bfb2a8d94f6c4a404a434742ef1df65
diff --git a/authfs/Android.bp b/authfs/Android.bp
index 8dabbd9..16d0b3a 100644
--- a/authfs/Android.bp
+++ b/authfs/Android.bp
@@ -21,6 +21,7 @@
         "libstructopt",
         "libthiserror",
     ],
+    prefer_rlib: true,
     target: {
         darwin: {
             enabled: false,