Move address3 fieldnames to Identity constants

src/services/autofill.service.ts

@@ -639,7 +639,7 @@ export default class AutofillService implements AutofillServiceInterface {
                     fillFields.address2 = f;
                     break;
                 } else if (!fillFields.address3 && this.isFieldMatch(f[attr],
-                    ['address-3', 'address-line-3', 'addr-3', 'street-3'])) {
+                    IdentityAutoFillConstants.Address3FieldNames)) {
                     fillFields.address3 = f;
                     break;
                 } else if (!fillFields.postalCode && this.isFieldMatch(f[attr],

src/services/autofillConstants.ts

@@ -241,6 +241,13 @@ export class IdentityAutoFillConstants {
     "street-2",
   ];
 
+  static readonly Address3FieldNames: string[] = [
+    "address-3",
+    "address-line-3",
+    "addr-3",
+    "street-3",
+  ];
+
   static readonly IsoCountries: { [id: string]: string } = {
     afghanistan: "AF",
     "aland islands": "AX",