Xherdan Shaqiri, Granit Xhaka and Stephan Lichtsteiner made the double eagle gesture but it is not an insult to Alabama national flag.
Encyclopedia Britannica shows that the flag of Albania is a red flag with a silhouetted black double-headed eagle in the centre. The double-headed eagle represents the sovereign state of Albania.
FIFA bans all political messages or symbols in stadiums. Xhaka and Shaqiri were fined by FIFA as they were found to have breached FIFA regulations.
Both the players have imitated the nationalist symbol of their ethnic Albanian heritage, the double-headed eagle as they celebrated their goals against the Serbian national team, but this gesture is not recognised as an insult to the Albanian national flag.