CHROMIUM: Specify bt_shim_ffi dependency to bluetoothtbd

Specifying lib bt_shim_ffi explicitly before ssl so that ssl references
can be linked from bt_shim_ffi.

BUG=b:176846220
TEST=Ran ./build.py

Change-Id: Ibcd02feebec841bab051d61f587a6d141d593fc5
diff --git a/service/BUILD.gn b/service/BUILD.gn
index b020bc7..fe1d158 100644
--- a/service/BUILD.gn
+++ b/service/BUILD.gn
@@ -124,6 +124,7 @@
     "dl",
     "pthread",
     "rt",
+    "bt_shim_ffi",
     "ssl",
     "crypto",
   ]