Add ContactsStorageSettingsActivity to handle the

android.provider.action.SET_DEFAULT_ACCOUNT intent

Test:Manually tested to trigger the contacts storage settings page using intent to start activity.
Bug: 368641291
Flag: com.android.settings.flags.enable_contacts_default_account_in_settings

Change-Id: I83db4c5751c6fec523298a82b82468180906075c