Merge changes from topics "splash_api_sc_a2", "splash_api_sc_a3",...

Merge changes from topics "splash_api_sc_a2", "splash_api_sc_a3", "splash_api_sc_a4", "splash_api_sc_a5", "splash_api_sc_a6", "splash_exit_sc_a1" into sc-dev

* changes:
  Add two more Api for SplashScreenView(7/N)
  Support persist night mode for application(6/N)
  Allow ShortcutInfo to specify a theme for splash screen.(5/N)
  Add API for show branding image on splash screen.(4/N)
  Provide new APIs for customize splash screen window.(3/N)
  Customizable exit splash screen animation.(2/N)