2835 Fix typo in image_picker_for_web README.md (cla: yes, p: image_picker, platform-web)

2846 [in_app_purchase] Typos in comments (cla: yes, p: in_app_purchase, waiting for tree to go green)

2858 [url_launcher] Update description in pubspec.yaml (cla: yes, p: url_launcher)

2983 [local_auth] Unnecessary reassignment in example removed (cla: yes, p: local_auth, waiting for tree to go green)