fix(IoT): Fixing auto reconnection not working properly.

[sebaland]

Issue #, if available:

• AWSIoT Automatic reconnection doesn't work when the app is suspended by the system (possible v2.33.9 regression) #5198

Description of changes:

This PR addresses an issue introduced in the refactor made on #5185.
When a reconnection happens, neither the session nor the streams are recreated (i.e. the existing ones are reused), so the AWSIoTStreamThread should not close them when it gets cancelled because of a reconnection.

I've solved this issue by creating a new cancelAndDisconnect: method that can be invoked with the proper flag when creating a new thread, i.e. self.userDidIssueDisconnect. A reconnection then would keep all the streams open and continue to receive updates.

Check points:

• Added new tests to cover change, if needed
• All unit tests pass
• All integration tests pass
• Updated CHANGELOG.md
• Documentation update for the change if required
• PR title conforms to conventional commit style

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[harsh62]

LGTM