Fix 2.6 NoSuchElementException in AA code. (#11734)

This would happen if a unit has special chars in its aaType, causing it to be evaluated as a regex instead of an exact match.
This specifically broke the code pattern (e.g. in FiringGroupSplitterAa):

    final List<String> typeAas = UnitAttachment.getAllOfTypeAas(aaUnits);
    for (final String typeAa : typeAas) {
      final Collection<Unit> firingUnits =
          CollectionUtils.getMatches(aaUnits, Matches.unitIsAaOfTypeAa(typeAa));

Causing an empty `firingUnits` due to typeAa being evaluated as a regex.
I checked all the callsites and verified none of them actually require the regex behavior.

Fixes: #11458

game-app/game-core/src/main/java/games/strategy/triplea/delegate/Matches.java

@@ -669,7 +669,7 @@ private static Predicate<UnitType> unitTypeCanBeHitByAaFire(
   }
 
   public static Predicate<Unit> unitIsAaOfTypeAa(final String typeAa) {
-    return u -> u.getUnitAttachment().getTypeAa().matches(typeAa);
+    return u -> u.getUnitAttachment().getTypeAa().equals(typeAa);
   }
 
   public static Predicate<Unit> unitAaShotDamageableInsteadOfKillingInstantly() {