Tabletize Device administrator screen and fix the layout for DeviceAdminAdd.

Bug: 3376986

Convert the DeviceAdminSettings screen to a fragment, remove fat titlebar.
Convert the DeviceAdminAdd screen to layout nicely in the new holo DialogWhenLarge
style.

Change-Id: I20a9d16aed135a2178969dfff807075b0b79237c

src/com/android/settings/Settings.java

@@ -333,4 +333,5 @@ public class Settings extends PreferenceActivity implements ButtonBarHandler {
     public static class AccountSyncSettingsActivity extends Settings { }
     public static class AccountSyncSettingsInAddAccountActivity extends Settings { }
     public static class CryptKeeperSettingsActivity extends Settings { }
+    public static class DeviceAdminSettingsActivity extends Settings { }
 }