3337 [camera] Add implementation of didFinishProcessingPhoto callback (iOS) (cla: yes)

3338 [camera] Add implementations for the torch flash mode. (cla: yes)

3339 Remove custom null safety analysis_options files (cla: yes, waiting for tree to go green)

3342 Fix test exclusion logic for nnbd plugins (cla: yes)

3344 [camera] Fixed stale images in imageStream subscriptions (cla: yes)

3345 [camera_platform_interface] Add platform interface methods for setting auto exposure. (cla: yes)

3346 [camera] Add iOS and Android implementations for managing auto exposure. (cla: yes)

3347 Upgrade CocoaPods in Cirrus (cla: yes)