Feature/1724/missed call notification

[mahibi]

this PR will:

• resolve show notifications for missed calls (+ improve duration for ringing) #1724
  • 
• convert some classes from java to kotlin
• introduce refactoring of Notification handling (isolate firebase stuff from other logic)
  • All "UI-notification" logic from ChatAndCallMessagingService was moved to NotificationWorker. ChatAndCallMessagingService was renamed to NCFirebaseMessagingService because it is now only responsible for firebase stuff. This separation should make it easier for alternative push services to dock with the app (if they are incorporated in the future).

Notes

• please note that for the next release, minSDK should be at least 23 in order to support the method notificationManager.activeNotifications. This method is already in use (which might introduced problems for older phones in the past) but it is further used with this PR.
  • Bumping the minSDK will happen in Set minSdkVersion to 23 (Android 6) II #2449
• this PR should not improve or worsen the reliability of notification delivery. However i expect the following impact of the "you missed a call" notifications on phones that are already known to have problems with on-time delivery:
  • if there were problems with on-time delivery and it starts to work again (e.g. after a phone restart), the user might get a bunch of too late delivered notifications at once (this might already happened for text messages, but now also for missed calls).

possible follow up PR's:

• NotificationWorker still needs to be further simplified!

[nextcloud-android-bot]

Lint

Type	master	PR
Warnings	112	112
Errors	1	1

SpotBugs (new)

Warning Type	Number
Bad practice Warnings	4
Correctness Warnings	33
Experimental Warnings	2
Internationalization Warnings	9
Malicious code vulnerability Warnings	10
Performance Warnings	22
Security Warnings	2
Dodgy code Warnings	54
Total	136

SpotBugs (master)

Warning Type	Number
Bad practice Warnings	4
Correctness Warnings	33
Experimental Warnings	2
Internationalization Warnings	9
Malicious code vulnerability Warnings	10
Performance Warnings	22
Security Warnings	2
Dodgy code Warnings	54
Total	136

[mahibi]

detekt checks are not fully satisfied. Some of the checks fail with ComplexMethod. While this is true and should be resolved in general, i suggest to review/merge anyway because this PR already changed a lot and seems stable for me. Further refactoring might take place in follow up PR's (after my vacation or later).

feel free to improve minor things in this PR while reviewing @timkrueger

[timkrueger]

The new notifications works as expected. But for the debug information I got a negative delay:

I'll try to look into it today or tomorrow.

Regarding the detekt issues I'm OK with merging them and resolve them afterwards in a separate PR.

[mahibi]

The new notifications works as expected. But for the debug information I got a negative delay:

i reverted the calculation of the delivery time. This doesn't make sense because time is not synchronized... in the future we may be able to trigger a test push from the device itself and measure the full roundtrip time until it is received on the device again. But calculating a difference to a timestamp from firebease server doesn't make sense because it's not time-synchronized and never will be.

[github-actions]

APK file: https://www.kaminsky.me/nc-dev/android-artifacts/2415-talk.apk



To test this change/fix you can simply download above APK file and install and test it in parallel to your existing Nextcloud Talk app.

[github-actions]

Codacy

Lint

Type	master	PR
Warnings	112	112
Errors	1	1

SpotBugs

Category	Base	New
Bad practice	4	4
Correctness	75	68
Dodgy code	315	272
Experimental	2	2
Internationalization	9	7
Malicious code vulnerability	53	53
Performance	23	22
Security	2	2
Total	483	430