Prevent apply system insets on splash screen from FITS_SYSTEM_WINDOWS

Similar to b/191339594, the context from application contains
View_fitsSystemWindows attributes, thus apply system insets to the
root FrameLayout.

Fixes: 192404431
Test: manual launch several apps from Launcher/Notification.
Tets: atest SplashscreenTests
Change-Id: I4746550de5e2a35ec364e09b631e87b41556a8b9