build: enable TSLint on the packages folder (#18459)

porting PRs #18392 and #18441 to 4.x

packages/platform-browser/test/security/html_sanitizer_spec.ts

@@ -123,7 +123,7 @@ export function main() {
         // depending on the browser, we might ge an exception
       }
       try {
-        sanitizeHtml(defaultDoc, '<form><input name="nextSibling" /></form>')
+        sanitizeHtml(defaultDoc, '<form><input name="nextSibling" /></form>');
       } catch (e) {
         // depending on the browser, we might ge an exception
       }