bump to 5.2.0

CHANGELOG.md

+# 5.2.0
+* 为iOS分享小程序增加hdImageData选项
+* 优化Android图片分享逻辑，优先把LocalImagePath以最大限度保证图片质量
+
 # 5.1.0
 * 试验性支持harmonyOS，目前受限于native sdk，只支持部分功能
 

pubspec.yaml

 name: fluwx
 description: The capability of implementing WeChat SDKs in Flutter. With Fluwx, developers can use WeChatSDK easily, such as sharing, payment, lanuch mini program and etc.
-version: 5.1.0
+version: 5.2.0
 homepage: https://github.com/OpenFlutter/fluwx
 
 environment: