fix: launch CallActivity when call is picked from notification

- add CallActivity.getStartIntent method to get the start intent for CallActivity and update in CallNotificationManager and CallService where the CallActivity is started
- in CallActionReceiver, start the CallActivity before answering the call

app/src/main/kotlin/com/simplemobiletools/dialer/activities/CallActivity.kt

@@ -3,6 +3,7 @@ package com.simplemobiletools.dialer.activities
 import android.annotation.SuppressLint
 import android.app.KeyguardManager
 import android.content.Context
+import android.content.Intent
 import android.graphics.Bitmap
 import android.media.AudioManager
 import android.os.Bundle
@@ -29,6 +30,14 @@ import kotlinx.android.synthetic.main.activity_call.*
 import kotlinx.android.synthetic.main.dialpad.*
 
 class CallActivity : SimpleActivity() {
+    companion object {
+        fun getStartIntent(context: Context): Intent {
+            val openAppIntent = Intent(context, CallActivity::class.java)
+            openAppIntent.flags = Intent.FLAG_ACTIVITY_BROUGHT_TO_FRONT or Intent.FLAG_ACTIVITY_NEW_TASK
+            return openAppIntent
+        }
+    }
+
     private var isSpeakerOn = false
     private var isMicrophoneOn = true
     private var isCallEnded = false

app/src/main/kotlin/com/simplemobiletools/dialer/helpers/CallNotificationManager.kt

@@ -39,8 +39,7 @@ class CallNotificationManager(private val context: Context) {
                 }
             }
 
-            val openAppIntent = Intent(context, CallActivity::class.java)
+            val openAppIntent = CallActivity.getStartIntent(context)
-            openAppIntent.flags = Intent.FLAG_ACTIVITY_BROUGHT_TO_FRONT
             val openAppPendingIntent = PendingIntent.getActivity(context, 0, openAppIntent, 0)
 
             val acceptCallIntent = Intent(context, CallActionReceiver::class.java)

app/src/main/kotlin/com/simplemobiletools/dialer/receivers/CallActionReceiver.kt

@@ -3,6 +3,7 @@ package com.simplemobiletools.dialer.receivers
 import android.content.BroadcastReceiver
 import android.content.Context
 import android.content.Intent
+import com.simplemobiletools.dialer.activities.CallActivity
 import com.simplemobiletools.dialer.helpers.ACCEPT_CALL
 import com.simplemobiletools.dialer.helpers.CallManager
 import com.simplemobiletools.dialer.helpers.DECLINE_CALL
@@ -10,7 +11,10 @@ import com.simplemobiletools.dialer.helpers.DECLINE_CALL
 class CallActionReceiver : BroadcastReceiver() {
     override fun onReceive(context: Context, intent: Intent) {
         when (intent.action) {
-            ACCEPT_CALL -> CallManager.accept()
+            ACCEPT_CALL -> {
+                context.startActivity(CallActivity.getStartIntent(context))
+                CallManager.accept()
+            }
             DECLINE_CALL -> CallManager.reject()
         }
     }

app/src/main/kotlin/com/simplemobiletools/dialer/services/CallService.kt

@@ -1,6 +1,5 @@
 package com.simplemobiletools.dialer.services
 
-import android.content.Intent
 import android.telecom.Call
 import android.telecom.InCallService
 import com.simplemobiletools.dialer.activities.CallActivity
@@ -18,9 +17,7 @@ class CallService : InCallService() {
 
     override fun onCallAdded(call: Call) {
         super.onCallAdded(call)
-        val intent = Intent(this, CallActivity::class.java)
+        startActivity(CallActivity.getStartIntent(this))
-        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
-        startActivity(intent)
         CallManager.call = call
         CallManager.inCallService = this
         CallManager.registerCallback(callListener)