multi: rename experimental endorsement signal to accountable

Renames the endorsement signal to accountable to
match the latest proposal https://github.com/lightning/blips/pull/67

itest/lnd_forward_interceptor_test.go

@@ -387,7 +387,7 @@ func testForwardInterceptorRestart(ht *lntest.HarnessTest) {
 	// all intercepted packets. These packets are held to simulate a
 	// pending payment.
 	packet := ht.ReceiveHtlcInterceptor(bobInterceptor)
-	require.Equal(ht, lntest.CustomRecordsWithUnendorsed(
+	require.Equal(ht, lntest.CustomRecordsWithUnaccountable(
 		customRecords,
 	), packet.InWireCustomRecords)
 
@@ -433,21 +433,21 @@ func testForwardInterceptorRestart(ht *lntest.HarnessTest) {
 	packet = ht.ReceiveHtlcInterceptor(bobInterceptor)
 
 	// Check the expected number of custom records based on whether the
-	// endorsement experiment is still active.
+	// accountability experiment is still active.
 	expectedLen := 1
-	if lntest.ExperimentalEndorsementActive() {
+	if lntest.ExperimentalAccountabilityActive() {
 		expectedLen = 2
 	}
 	require.Len(ht, packet.InWireCustomRecords, expectedLen)
-	require.Equal(ht, lntest.CustomRecordsWithUnendorsed(customRecords),
+	require.Equal(ht, lntest.CustomRecordsWithUnaccountable(customRecords),
 		packet.InWireCustomRecords)
 
 	// And now we forward the payment at Carol, expecting only an
-	// endorsement signal in our incoming custom records (if the experiment
+	// accountability signal in our incoming custom records (if the experiment
 	// is still active).
 	packet = ht.ReceiveHtlcInterceptor(carolInterceptor)
 	expectedCarolLen := 0
-	if lntest.ExperimentalEndorsementActive() {
+	if lntest.ExperimentalAccountabilityActive() {
 		expectedCarolLen = 1
 	}
 	require.Len(ht, packet.InWireCustomRecords, expectedCarolLen)
@@ -462,7 +462,7 @@ func testForwardInterceptorRestart(ht *lntest.HarnessTest) {
 		alice, preimage.Hash(), lnrpc.Payment_SUCCEEDED,
 		func(p *lnrpc.Payment) error {
 			recordsEqual := reflect.DeepEqual(
-				lntest.CustomRecordsWithUnendorsed(
+				lntest.CustomRecordsWithUnaccountable(
 					sendReq.FirstHopCustomRecords,
 				), p.FirstHopCustomRecords,
 			)