Strip part of 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.

However, removing the entire info may result in app compatibility
issues. So, only swiping the info that are sensitive to empty
string.

Bug: 243130512
Test: verified market app locally
Test: atest RecentTasksTest
Change-Id: I5b6775dd3c4e2ccdacd30741884d336b2eaa70da
(cherry picked from commit 5ba72200)
Merged-In: I5b6775dd3c4e2ccdacd30741884d336b2eaa70da