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/usage/UsageStatsManager.java b/core/java/android/app/usage/UsageStatsManager.java
index 72d209a..0994332 100644
--- a/core/java/android/app/usage/UsageStatsManager.java
+++ b/core/java/android/app/usage/UsageStatsManager.java
@@ -21,6 +21,7 @@
 import android.annotation.RequiresPermission;
 import android.annotation.SystemApi;
 import android.annotation.SystemService;
+import android.annotation.UnsupportedAppUsage;
 import android.app.PendingIntent;
 import android.content.Context;
 import android.content.pm.ParceledListSlice;
@@ -231,9 +232,12 @@
     @SystemApi
     public static final String EXTRA_TIME_USED = "android.app.usage.extra.TIME_USED";
 
+    @UnsupportedAppUsage
     private static final UsageEvents sEmptyResults = new UsageEvents();
 
+    @UnsupportedAppUsage
     private final Context mContext;
+    @UnsupportedAppUsage
     private final IUsageStatsManager mService;
 
     /**