Populate Enterprise Privacy Settings page - batch 1

This CL adds the first batch of items to the Privacy Settings page.
These are all the items that fall into the "What types of
information can your organization see?" category and do not require
deeper Framework changes. Further batches are to come in separate
CLs.

Test: make RunSettingsRoboTests
Bug: 32692748
Change-Id: I460093bc45ed0e5baab2a5cdf9833e654d436cc9

src/com/android/settings/applications/ApplicationFeatureProvider.java

@@ -25,5 +25,17 @@ public interface ApplicationFeatureProvider {
      * Returns a new {@link AppHeaderController} instance to customize app header.
      */
     AppHeaderController newAppHeaderController(Fragment fragment, View appHeader);
-}
 
+    /**
+     * Asynchronously calculates the total number of apps installed on the device, across all users
+     * and managed profiles.
+     */
+    void calculateNumberOfInstalledApps(NumberOfInstalledAppsCallback callback);
+
+    /**
+     * Callback that receives the total number of packages installed on the device.
+     */
+    public interface NumberOfInstalledAppsCallback {
+        void onNumberOfInstalledAppsResult(int num);
+    }
+}