[improvement] rename packages dir to src (#3659)

src/utils/validate/system.ts

@@ -0,0 +1,11 @@
+import { isServer } from '..';
+
+export function isAndroid(): boolean {
+  /* istanbul ignore next */
+  return isServer ? false : /android/.test(navigator.userAgent.toLowerCase());
+}
+
+export function isIOS(): boolean {
+  /* istanbul ignore next */
+  return isServer ? false : /ios|iphone|ipad|ipod/.test(navigator.userAgent.toLowerCase());
+}