User management and switching

Broadcast intents that get sent out when users are added/removed/switched.

More work on generating user-specific information in package manager queries.
APIs to update user name and query a user by id.
Removed Package.mSetStopped and mSetEnabled, since they're not user specific.

User removal:
- Cleanup ActivityManager, PackageManager, WallpaperManager, AppWidgetService
  and AccountManager.
- Shutdown processes belonging to the user.

Don't show vibrate option in long-press power if there's no vibrator.

Lock the screen when switching users, to force unlocking.

Change-Id: Ib23a721cb75285eef5fd6ba8c7272462764038fa

services/java/com/android/server/AppWidgetServiceImpl.java

@@ -1484,9 +1484,13 @@ class AppWidgetServiceImpl {
         }
     }
 
+    static File getSettingsFile(int userId) {
+        return new File("/data/system/users/" + userId + "/" + SETTINGS_FILENAME);
+    }
+
     AtomicFile savedStateFile() {
         File dir = new File("/data/system/users/" + mUserId);
-        File settingsFile = new File(dir, SETTINGS_FILENAME);
+        File settingsFile = getSettingsFile(mUserId);
         if (!dir.exists()) {
             dir.mkdirs();
             if (mUserId == 0) {
@@ -1500,6 +1504,16 @@ class AppWidgetServiceImpl {
         return new AtomicFile(settingsFile);
     }
 
+    void onUserRemoved() {
+        // prune the ones we don't want to keep
+        int N = mInstalledProviders.size();
+        for (int i = N - 1; i >= 0; i--) {
+            Provider p = mInstalledProviders.get(i);
+            cancelBroadcasts(p);
+        }
+        getSettingsFile(mUserId).delete();
+    }
+
     void addProvidersForPackageLocked(String pkgName) {
         Intent intent = new Intent(AppWidgetManager.ACTION_APPWIDGET_UPDATE);
         intent.setPackage(pkgName);