Fix flowlog crash

While creating FlowLog, if logDestnation does not exist then
CreateFlowLogsWithContext does not return the error. However,
Unsuccessful field in the response is set. FlowLog is not created in
aws. Due to this, controller crashes while accessing the flow log id
from the response (resp.FlowLogIds[0]).
Fixing the issue by checking if FlowLogIds has valid length before
accessing it.

Author: Nishant Burte

pkg/resource/flow_log/sdk.go

@@ -1,3 +1,3 @@
-    if resp.FlowLogIds[0] != nil {
+    if len(resp.FlowLogIds) > 0 && resp.FlowLogIds[0] != nil {
 		ko.Status.FlowLogID = resp.FlowLogIds[0]
 	}