Implement new splash screen API

Test: mmm frameworks/base/tests/ActivityTests, launch
CustomSplashscreenActivity
Test: android.server.android.server.cts.SplashscreenTests

Bug: 37252694
Change-Id: Ie2aec4764d958086897296ed0fc3c39c55c4d8aa
Merged-In: I9a5bc19b8f63312e682e536500411e4ff4639f88
10 files changed