[iOS] Declining Incoming Call to SIM number triggers `endCall` event

Bug report

• I've checked the example to reproduce the issue.

Reproduced on:

• Android
• iOS

Description

When using Callkeep to display an outbound call from our app and an incoming call comes in to the SIM on the phone, CallKit displays the incoming call with the option to decline or answer. Declining the call triggers the RNCallKeep endCall event with the callUUID from the outbound call instead.

This means that declining an inbound call to the phone will end the call in the app as it looks exactly like when a user presses the End Call button on CallKit.

Steps to Reproduce

• Make an outbound call with RNCallKeep.startCall
• Receive an incoming call to the SIM on the phone
• CallKit displays Decline and Answer options
• Press Decline for the call incoming
• endCall event is triggered with the callUUID from RNCallKeep.startCall

Versions

- Callkeep: 4.3.12
- React Native: 0.72.6
- iOS: 17.1
- Android: N/A
- Phone model: iPhone 14 Pro 

Logs

N/A

Start by reproducing the iOS flow with RNCallKeep.startCall, an incoming SIM call, and CallKit's Decline action on the listed versions. Trace how the endCall event receives the outbound callUUID; done means declining the SIM call no longer ends the app's outbound call or emits that UUID as an endCall event.