fix: update Schema service to use new API endpoint

x/vault/keeper/querier.go

@@ -40,3 +40,16 @@ func (k Querier) BuildTx(goCtx context.Context, req *types.BuildTxRequest) (*typ
 	// ctx := sdk.UnwrapSDKContext(goCtx)
 	return &types.BuildTxResponse{}, nil
 }
+
+// Schema implements types.QueryServer.
+func (k Querier) Schema(goCtx context.Context, req *types.QuerySchemaRequest) (*types.QuerySchemaResponse, error) {
+	ctx := sdk.UnwrapSDKContext(goCtx)
+
+	p, err := k.Keeper.Params.Get(ctx)
+	if err != nil {
+		return nil, err
+	}
+	return &types.QuerySchemaResponse{
+		Schema: p.Schema,
+	}, nil
+}