Hide clock option when there is only 1 option[1/2]

- Not to add clock option(tab) to home page when there is only 1 option
- By default, there should be only 1 clock(Default clock) build-in with device, additional clock content will be provided by another apk, if can not find that apk means we only have 1 clock option, then hide the clock tab

Bug: 146530441
Test: Need work with ag/10361873, modify the mk file to build up additional clock content, then check the Picker app will display Clock tab or not.

Change-Id: Ie64e6f0074869792a956d6b47e4f483a2bbd531f