Apply insets correctly to fallback Recents Go

Insets were not being correctly consumed by the root view in the
fallback recents activity. This CL properly passes on the system insets
to the recents view so that tasks flow under the system insets.

Bug: 131853975
Test: Have separate default launcher, go to recents, go to landscape,
tasks scroll under status bar
Change-Id: I16f78da896522c5cf41951817747a24cd5cfe32c