[wifi_info_flutter] Migrate the platform interface to null safety (fl…

…utter#3424)

Update video_player_platform_interface to latest pigeon (flutter#3507)

See flutter#3281 for context.

Update video_player_platform_interface to latest pigeon (flutter#3507)

See flutter#3281 for context.

Update video_player_platform_interface to latest pigeon (flutter#3507)

See flutter#3281 for context.

[sensors] Migrate to null safety (flutter#3423)

[quick_actions] Migrate to null safety (flutter#3421)

[shared_preferences] Migrate platform plugins to null-safety (flutter…

…#3523)

Migrates shared_preferences_linux and shared_preferences_web to null-safety.

[file_selector_platform_interface] File selector nnbd (flutter#3509)

Migrating file_selector_interface to null-safety

[camera_platform_interface] Migrate to null safety (flutter#3497)

[camera_platform_interface] Migrate to null safety (flutter#3497)