add flag for enable/disable call function

Session/Calls/Call Management/SessionCall.swift

@@ -5,6 +5,9 @@ import PromiseKit
 import CallKit
 
 public final class SessionCall: NSObject, WebRTCSessionDelegate {
+    
+    @objc static let isEnabled = true
+    
     // MARK: Metadata Properties
     let uuid: String
     let callID: UUID // This is for CallKit

Session/Conversations/ConversationVC+Interaction.swift

@@ -28,6 +28,7 @@ extension ConversationVC : InputViewDelegate, MessageCellDelegate, ContextMenuAc
     
     // MARK: Call
     @objc func startCall(_ sender: Any?) {
+        guard SessionCall.isEnabled else { return }
         let userDefaults = UserDefaults.standard
         if !SSKPreferences.areCallsEnabled && !userDefaults[.hasSeenCallIPExposureWarning] {
             userDefaults[.hasSeenCallIPExposureWarning] = true

Session/Conversations/ConversationVC.swift

@@ -309,7 +309,7 @@ final class ConversationVC : BaseVC, ConversationViewModelDelegate, OWSConversat
                 settingsButton.accessibilityLabel = "Settings button"
                 settingsButton.isAccessibilityElement = true
                 rightBarButtonItems.append(settingsButton)
-                let shouldShowCallButton = !thread.isNoteToSelf() && (SSKPreferences.areCallsEnabled || !UserDefaults.standard[.hasSeenCallIPExposureWarning])
+                let shouldShowCallButton = SessionCall.isEnabled && !thread.isNoteToSelf() && (SSKPreferences.areCallsEnabled || !UserDefaults.standard[.hasSeenCallIPExposureWarning])
                 if shouldShowCallButton {
                     let callButton = UIBarButtonItem(image: UIImage(named: "Phone")!, style: .plain, target: self, action: #selector(startCall))
                     rightBarButtonItems.append(callButton)

Session/Conversations/Views & Modals/ConversationTitleView.swift

@@ -44,7 +44,7 @@ final class ConversationTitleView : UIView {
         stackView.axis = .vertical
         stackView.alignment = .center
         stackView.isLayoutMarginsRelativeArrangement = true
-        let shouldShowCallButton = !thread.isNoteToSelf() && !thread.isGroupThread() && (SSKPreferences.areCallsEnabled || !UserDefaults.standard[.hasSeenCallIPExposureWarning])
+        let shouldShowCallButton = SessionCall.isEnabled && !thread.isNoteToSelf() && !thread.isGroupThread() && (SSKPreferences.areCallsEnabled || !UserDefaults.standard[.hasSeenCallIPExposureWarning])
         let leftMargin: CGFloat = shouldShowCallButton ? 54 : 8 // Contact threads also have the call button to compensate for
         stackView.layoutMargins = UIEdgeInsets(top: 0, left: leftMargin, bottom: 0, right: 0)
         addSubview(stackView)