android notif [nfc]: Rename file to NotificationUiManager

This makes a much more on-point name for what this file actually does.
It doesn't have anything particularly to do with FCM at all; that's
the job of some other code (and not very much of it.)  Rather its job
is to maintain the set of notifications as they appear in the UI.

The reason it was named this is just that that's what it had always
been; converted from FCMPushNotifications.java in 5654221, and
before that renamed from GCMPushNotifications.java in f180171,
both early 2019.

And that in turn dates to when the first version of this code was
written in 2017, where it was entangled with a pretty chaotic
third-party library from the RN universe.  (See e.g. 30e4d8e,
and the rest of the changes leading up to d048dba.)

android/app/src/main/java/com/zulipmobile/MainApplication.java

@@ -20,7 +20,7 @@
 import org.unimodules.core.interfaces.SingletonModule;
 
 import com.zulipmobile.generated.BasePackageList;
-import com.zulipmobile.notifications.FCMPushNotifications;
+import com.zulipmobile.notifications.NotificationUiManager;
 import com.zulipmobile.notifications.NotificationsPackage;
 import com.zulipmobile.sharing.SharingPackage;
 
@@ -69,7 +69,7 @@ public ReactNativeHost getReactNativeHost() {
     @Override
     public void onCreate() {
         super.onCreate();
-        FCMPushNotifications.createNotificationChannel(this);
+        NotificationUiManager.createNotificationChannel(this);
         SoLoader.init(this, /* native exopackage */ false);
         initializeFlipper(this, getReactNativeHost().getReactInstanceManager());
     }

android/app/src/main/java/com/zulipmobile/notifications/FcmListenerService.java

@@ -15,7 +15,7 @@ public void onMessageReceived(RemoteMessage message) {
         if (!(applicationContext instanceof MainApplication)) {
             return;
         }
-        FCMPushNotifications.onReceived(this, message.getData());
+        NotificationUiManager.onReceived(this, message.getData());
     }
 
     @Override

android/app/src/main/java/com/zulipmobile/notifications/NotificationIntentService.java

@@ -9,8 +9,8 @@
 import com.zulipmobile.MainApplication;
 
 import static android.content.Intent.ACTION_VIEW;
-import static com.zulipmobile.notifications.FCMPushNotifications.ACTION_CLEAR;
-import static com.zulipmobile.notifications.FCMPushNotifications.EXTRA_NOTIFICATION_DATA;
+import static com.zulipmobile.notifications.NotificationUiManager.ACTION_CLEAR;
+import static com.zulipmobile.notifications.NotificationUiManager.EXTRA_NOTIFICATION_DATA;
 
 public class NotificationIntentService extends IntentService {
     public NotificationIntentService() {
@@ -25,7 +25,7 @@ protected void onHandleIntent(Intent intent) {
         }
         if (ACTION_VIEW.equals(intent.getAction())) {
             final Bundle data = intent.getBundleExtra(EXTRA_NOTIFICATION_DATA);
-            FCMPushNotifications.onOpened((ReactApplication) getApplication(), data);
+            NotificationUiManager.onOpened((ReactApplication) getApplication(), data);
         }
     }
 }

android/app/src/main/java/com/zulipmobile/notifications/FCMPushNotifications.kt → android/app/src/main/java/com/zulipmobile/notifications/NotificationUiManager.kt

@@ -1,4 +1,4 @@
-@file:JvmName("FCMPushNotifications")
+@file:JvmName("NotificationUiManager")
 
 package com.zulipmobile.notifications
 

docs/architecture/notifications.md

@@ -41,7 +41,7 @@ iOS we haven't implemented all the same notification features.)
 
 For the implementation of our UI notifications, see:
 
- * on Android, our [`FCMPushNotifications.kt`][FCMPushNotifications.kt]
+ * on Android, our [`NotificationUiManager.kt`][NotificationUiManager.kt]
 
  * on iOS, the server code in
    [`push_notifications.py`][push_notifications.py] that generates the
@@ -52,7 +52,7 @@ For the implementation of our UI notifications, see:
    notification, without involving any client-side code of our own.
 
 [FcmMessage.kt]: ../../android/app/src/main/java/com/zulipmobile/notifications/FcmMessage.kt
-[FCMPushNotifications.kt]: ../../android/app/src/main/java/com/zulipmobile/notifications/FCMPushNotifications.kt
+[NotificationUiManager.kt]: ../../android/app/src/main/java/com/zulipmobile/notifications/NotificationUiManager.kt
 [push_notifications.py]: https://github.com/zulip/zulip/blob/main/zerver/lib/push_notifications.py
 [apns-payload]: https://developer.apple.com/documentation/usernotifications/setting_up_a_remote_notification_server/generating_a_remote_notification