Example apps crash if the stop method is called when the lifecycle manager errors

[NicoleYarroch]

Bug Report

If the start:readyHandler method errors, the app crashes because it attempts to stop the manager on the same queue, which causes deadlock.

The example app should follow the library's documentation and only stop the manager on the main thread. (#1213)

The app errors out when:

1. If the RegisterAppInterface fails with a result code of DISALLOWED, the example apps in the library (Swift and Obj-C) crash.
2. The RegisterAppInterface fails because the session terminated. Failed to register the app. Error: Error Domain=com.sdl.lifecyclemanager.error Code=-2 "Could not find a connection". This happens when the USB cord is pulled after sending a RAI request but before a response is received.

Reproduction Steps for error 1

1. Create two SDL apps (A and B) using the same app name and app id.
2. Install both apps on the phone and connect phone to TDK
3. One app's RegisterAppInterface request will fail with a resultCode of APPLICATION_REGISTERED_ALREADY

Expected Behavior

The device app does not crash.

Observed Behavior

The device app crashes

OS & Version Information

• iOS Version: n/a
• SDL iOS Version: 6.2
• Testing Against: SYNC 3 TDK

[NicoleYarroch]

Closed via PR #1248