Add @UnsupportedAppUsage annotations

For packages:
  android.app.usage
  android.app.trust
  android.app.timezonedetector
  android.app.timezone
  android.app.timedetector
  android.app.job
  android.app.backup
  android.app.assist
  android.app.admin
  android.app

This is an automatically generated CL. See go/UnsupportedAppUsage
for more details.

Exempted-From-Owner-Approval: Mechanical changes to the codebase
which have been approved by Android API council and announced on
android-eng@

Bug: 110868826
Test: m
Change-Id: I618c5dc4462ae990d9df45c3e9ed3f092cc5138c
diff --git a/core/java/android/app/NotificationChannelGroup.java b/core/java/android/app/NotificationChannelGroup.java
index 0fa3c7f..17c5cba 100644
--- a/core/java/android/app/NotificationChannelGroup.java
+++ b/core/java/android/app/NotificationChannelGroup.java
@@ -17,6 +17,7 @@
 
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
+import android.annotation.UnsupportedAppUsage;
 import android.content.Intent;
 import android.os.Parcel;
 import android.os.Parcelable;
@@ -49,6 +50,7 @@
     private static final String ATT_ID = "id";
     private static final String ATT_BLOCKED = "blocked";
 
+    @UnsupportedAppUsage
     private final String mId;
     private CharSequence mName;
     private String mDescription;