paymentsdb: rename defaultKVStoreOptions func

We rename the modifier to use the same naming as used in the
graphDB to align the codebase.

payments/db/kv_store.go

@@ -133,18 +133,11 @@ type KVStore struct {
 	keepFailedPaymentAttempts bool
 }
 
-// defaultKVStoreOptions returns the default options for the KV store.
-func defaultKVStoreOptions() *StoreOptions {
-	return &StoreOptions{
-		KeepFailedPaymentAttempts: false,
-	}
-}
-
 // NewKVStore creates a new KVStore for payments.
 func NewKVStore(db kvdb.Backend,
 	options ...OptionModifier) (*KVStore, error) {
 
-	opts := defaultKVStoreOptions()
+	opts := DefaultOptions()
 	for _, applyOption := range options {
 		applyOption(opts)
 	}

payments/db/options.go

@@ -10,6 +10,14 @@ type StoreOptions struct {
 	KeepFailedPaymentAttempts bool
 }
 
+// DefaultOptions returns a StoreOptions populated with default values.
+func DefaultOptions() *StoreOptions {
+	return &StoreOptions{
+		KeepFailedPaymentAttempts: false,
+		NoMigration:               false,
+	}
+}
+
 // OptionModifier is a function signature for modifying the default
 // StoreOptions.
 type OptionModifier func(*StoreOptions)