tka: reduce boilerplate code in the tests

Updates #cleanup

Change-Id: Id69d509f5e470fb5fb50b5c5c4ca61f000389c53
Signed-off-by: Alex Chan <alexc@tailscale.com>

tka/deeplink_test.go

@@ -14,11 +14,7 @@ func TestGenerateDeeplink(t *testing.T) {
         G1 -> L1
 
         G1.template = genesis
-    `,
-		optTemplate("genesis", AUM{MessageKind: AUMCheckpoint, State: &State{
-			Keys:              []Key{key},
-			DisablementValues: [][]byte{DisablementKDF([]byte{1, 2, 3})},
-		}}),
+    `, genesisTemplate(key),
 	)
 	a, _ := Open(c.Chonk())