remove isGroupConversation variable

Signed-off-by: sowjanyakch <sowjanya.kch@gmail.com>

app/src/main/java/com/nextcloud/talk/activities/CallActivity.kt

@@ -352,7 +352,6 @@ class CallActivity : CallBaseActivity() {
     private var reactionAnimator: ReactionAnimator? = null
     private var othersInCall = false
     private var isOneToOneConversation = false
-    private var isGroupConversation = false
 
     private lateinit var micInputAudioRecorder: AudioRecord
     private var micInputAudioRecordThread: Thread? = null