Move city fieldnames to Identity constants

src/services/autofill.service.ts

@@ -647,7 +647,7 @@ export default class AutofillService implements AutofillServiceInterface {
                     fillFields.postalCode = f;
                     break;
                 } else if (!fillFields.city && this.isFieldMatch(f[attr],
-                    ['city', 'town', 'address-level-2', 'address-city', 'address-town'])) {
+                    IdentityAutoFillConstants.CityFieldNames)) {
                     fillFields.city = f;
                     break;
                 } else if (!fillFields.state && this.isFieldMatch(f[attr],

src/services/autofillConstants.ts

@@ -262,6 +262,14 @@ export class IdentityAutoFillConstants {
     "address-zip-code",
   ];
 
+  static readonly CityFieldNames: string[] = [
+    "city",
+    "town",
+    "address-level-2",
+    "address-city",
+    "address-town",
+  ];
+
   static readonly IsoCountries: { [id: string]: string } = {
     afghanistan: "AF",
     "aland islands": "AX",