3304 [ci][image_picker]enable xcode 12/iOS 14 for all tasks except lint (cla: yes, waiting for tree to go green)

3308 [documentation] [url_launcher] fix for readme code sample (cla: yes)

3309 Pass a Uri to package:http APIs (cla: yes, waiting for test harness)

3311 [share] Migrate to null-safety (cla: yes)

3312 [camera] Add zoom support to platform interface (cla: yes)

3313 [camera] Expanded platform interface to support setting flash mode (cla: yes)

3314 [camera] Flash functionality for Android and iOS (cla: yes)

3315 [camera] Zoom functionality for Android and iOS (cla: yes)