[sdk] Explicitly attach an id to the topaz SDK.

This id used to be carried over from the garnet SDK as a documentation
atom but now needs to be specified in the SDK metadata itself.

Bug: DX-979
Change-Id: Ifc8197d9946d2485bbc27f981de429fb54b5f126
diff --git a/public/sdk/BUILD.gn b/public/sdk/BUILD.gn
index 6518186..085dcbf 100644
--- a/public/sdk/BUILD.gn
+++ b/public/sdk/BUILD.gn
@@ -5,6 +5,7 @@
 import("//build/dart/toolchain.gni")
 import("//build/sdk/sdk.gni")
 import("//build/sdk/sdk_molecule.gni")
+import("//sdk/config.gni")
 
 # Tools and libraries required to generate and use FIDL bindings in Dart.
 sdk_molecule("fidl_dart") {
@@ -31,6 +32,8 @@
 sdk("topaz") {
   category = "partner"
 
+  id = sdk_id
+
   testonly = true
 
   deps = [