v2/services/mgmt,v/services/mgmt: install package override (server)

Server-side changes corresponding to go/vcl/3982.  In addition, we rename
application PackageSpec to SignedFile, and change the application Envelope to
use SignedFile instead of Binary + Signature fields.

Change-Id: Icd19faaad48aba7665c1805dbac7d5b1ee3dcc24
diff --git a/tools/mgmt/device/impl/local_install.go b/tools/mgmt/device/impl/local_install.go
index 21200c7..85cc430 100644
--- a/tools/mgmt/device/impl/local_install.go
+++ b/tools/mgmt/device/impl/local_install.go
@@ -271,7 +271,7 @@
 		return fmt.Errorf("failed to create server: %v", err)
 	}
 	defer cancel()
-	envelope.Binary, err = server.serve("binary", repository.BinaryServer(binaryInvoker(binary)))
+	envelope.Binary.File, err = server.serve("binary", repository.BinaryServer(binaryInvoker(binary)))
 	if err != nil {
 		return err
 	}
@@ -286,13 +286,13 @@
 	defer os.RemoveAll(tmpZipDir)
 	for _, p := range pkgs {
 		if envelope.Packages == nil {
-			envelope.Packages = make(map[string]application.PackageSpec)
+			envelope.Packages = make(application.Packages)
 		}
 		pname, oname, err := servePackage(p, server, tmpZipDir)
 		if err != nil {
 			return err
 		}
-		envelope.Packages[pname] = application.PackageSpec{File: oname}
+		envelope.Packages[pname] = application.SignedFile{File: oname}
 	}
 	packagesRewritten := application.Packages{}
 	for pname, pspec := range packagesOverride {