Add handling for account tiles for specific account type.

- List individual account instead of account type under User & account
  screen.

- Add handling to move account tiles with specific account type from
  top level account dashboard to inside the corresponding account
  preference.

- Rename settings.accounts.AccountPreference to
  settings.accounts.AccountTypePreference to make it less confused
  with settings.AccountPreference

Bug: 31801423
Test: make RunSettingsRoboTests
Change-Id: Iebe70a3c4230e8d979344f142a5c2a60945e552e

src/com/android/settings/dashboard/DashboardFragment.java

@@ -230,6 +230,13 @@ public abstract class DashboardFragment extends SettingsPreferenceFragment
      */
     protected abstract List<PreferenceController> getPreferenceControllers(Context context);
 
+    /**
+     * Returns true if this tile should be displayed
+     */
+    protected boolean displayTile(Tile tile) {
+        return true;
+    }
+
     /**
      * Displays resource based tiles.
      */
@@ -319,6 +326,9 @@ public abstract class DashboardFragment extends SettingsPreferenceFragment
                 Log.d(TAG, "tile does not contain a key, skipping " + tile);
                 continue;
             }
+            if (!displayTile(tile)) {
+                continue;
+            }
             if (mDashboardTilePrefKeys.contains(key)) {
                 // Have the key already, will rebind.
                 final Preference preference = mProgressiveDisclosureMixin.findPreference(