[connectivity] Update and migrate iOS example project

[jmagman]

Description

1. Let Move flutter_assets to App.framework flutter#26630 flutter_assets migrator run
2. Run pod install so flutter_assets is removed from the asset copy build phase
3. Migrate deprecated "English" to "en" language
4. Allow Xcode to remove extraneous xcconfigs, see Remove xcconfigs from template Copy Bundle Resources build phases flutter#38724
5. Let Xcode 11 update build settings
6. Remove DEVELOPMENT_TEAM references since having those provisioning profiles should not be required to run the examples (most examples don't have one)
7. Remove ARCHS, which was causing a compilation error

Related Issues

Get to a buildable baseline so I can start working on flutter/flutter#41007.

Checklist

• I read the [Contributor Guide] and followed the process outlined there for submitting PRs.
• My PR includes unit or integration tests for all changed/updated/fixed behaviors (See [Contributor Guide]).
• All existing and new tests are passing.
• I updated/added relevant documentation (doc comments with ///).
• The analyzer (flutter analyze) does not report any problems on my PR.
• I read and followed the [Flutter Style Guide].
• The title of the PR starts with the name of the plugin surrounded by square brackets, e.g. [shared_preferences]
• I updated pubspec.yaml with an appropriate new version according to the [pub versioning philosophy].
• I updated CHANGELOG.md to add a description of the change.
• I signed the [CLA].
• I am willing to follow-up on review comments in a timely manner.

Breaking Change

• Yes, this is a breaking change (please indicate a breaking change in CHANGELOG.md and increment major revision).
• No, this is not a breaking change.

[jmagman]

Does a change to the example app require a build suffix version bump?

[cyanglaz]

LGTM!