Implemented the mechanism of hiding clock face based on phenotype flag.

Created a string type of phenotype flag which contains the clock plugin
service names that are not allow to be shown. Each service name is
seperated by a comma(",").

Test: atest com.android.keyguard.clock.ClockManagerTest
Bug: 133406302
Change-Id: I51c00b03ec56eaf4de7cab91073deeeb73610f93