Unify and change notification channel to package name

Test: Manually
Bug: 378665160
Change-Id: I4b288dbb2a208b27c383f7d859e25022e900e55b
diff --git a/android/TerminalApp/java/com/android/virtualization/terminal/InstallerService.java b/android/TerminalApp/java/com/android/virtualization/terminal/InstallerService.java
index 2ce0cdc..b785416 100644
--- a/android/TerminalApp/java/com/android/virtualization/terminal/InstallerService.java
+++ b/android/TerminalApp/java/com/android/virtualization/terminal/InstallerService.java
@@ -54,7 +54,6 @@
 public class InstallerService extends Service {
     private static final String TAG = "InstallerService";
 
-    private static final String NOTIFICATION_CHANNEL_ID = "installer";
     private static final int NOTIFICATION_ID = 1313; // any unique number among notifications
 
     private static final String IMAGE_URL =
@@ -81,23 +80,12 @@
     public void onCreate() {
         super.onCreate();
 
-        // Create mandatory notification
-        NotificationManager manager = getSystemService(NotificationManager.class);
-        if (manager.getNotificationChannel(NOTIFICATION_CHANNEL_ID) == null) {
-            NotificationChannel channel =
-                    new NotificationChannel(
-                            NOTIFICATION_CHANNEL_ID,
-                            getString(R.string.installer_notif_title_text),
-                            NotificationManager.IMPORTANCE_DEFAULT);
-            manager.createNotificationChannel(channel);
-        }
-
         Intent intent = new Intent(this, MainActivity.class);
         PendingIntent pendingIntent =
                 PendingIntent.getActivity(
                         this, /* requestCode= */ 0, intent, PendingIntent.FLAG_IMMUTABLE);
         mNotification =
-                new Notification.Builder(this, NOTIFICATION_CHANNEL_ID)
+                new Notification.Builder(this, this.getPackageName())
                         .setSmallIcon(R.drawable.ic_launcher_foreground)
                         .setContentTitle(getString(R.string.installer_notif_title_text))
                         .setContentText(getString(R.string.installer_notif_desc_text))
diff --git a/android/TerminalApp/java/com/android/virtualization/terminal/MainActivity.java b/android/TerminalApp/java/com/android/virtualization/terminal/MainActivity.java
index fdf1f3b..e8fd2d2 100644
--- a/android/TerminalApp/java/com/android/virtualization/terminal/MainActivity.java
+++ b/android/TerminalApp/java/com/android/virtualization/terminal/MainActivity.java
@@ -95,15 +95,18 @@
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
-        boolean launchInstaller = installIfNecessary();
-
         NotificationManager notificationManager = getSystemService(NotificationManager.class);
-        if (notificationManager.getNotificationChannel(TAG) == null) {
-            NotificationChannel notificationChannel =
-                    new NotificationChannel(TAG, TAG, NotificationManager.IMPORTANCE_LOW);
-            notificationManager.createNotificationChannel(notificationChannel);
+        if (notificationManager.getNotificationChannel(this.getPackageName()) == null) {
+            NotificationChannel channel =
+                    new NotificationChannel(
+                            this.getPackageName(),
+                            getString(R.string.app_name),
+                            NotificationManager.IMPORTANCE_DEFAULT);
+            notificationManager.createNotificationChannel(channel);
         }
 
+        boolean launchInstaller = installIfNecessary();
+
         setContentView(R.layout.activity_headless);
         diskSizeStep = getResources().getInteger(
                 R.integer.disk_size_round_up_step_size_in_mb) << 20;
@@ -471,8 +474,7 @@
                         PendingIntent.FLAG_UPDATE_CURRENT | PendingIntent.FLAG_IMMUTABLE);
         Icon icon = Icon.createWithResource(getResources(), R.drawable.ic_launcher_foreground);
         Notification notification =
-                new Notification.Builder(this, TAG)
-                        .setChannelId(TAG)
+                new Notification.Builder(this, this.getPackageName())
                         .setSmallIcon(R.drawable.ic_launcher_foreground)
                         .setContentTitle(
                                 getResources().getString(R.string.service_notification_title))