Trim the activity info of another uid if no privilege

The activity info could be from another uid which is different
from the app that hosts the task. The information should be
trimmed if the caller app doesn't have the privilege.

Bug: 243130512
Test: verified locally
Test: atest RecentTasksTest
Change-Id: Ia343ac70e5bb9aeae718fca6674e1ca491a14512