[Partial Screensharing] Add enterprise policies handling flag

Adds a feature flag to enable/disable enterprise
policies handling in partial screen sharing feature.

Also adds a logic to forbid cross-profile sharing
using recent tasks when this flag is disabled.

Cross-profile sharing using the app selector
is already forbidden.

Bug: 233348916
Test: com.android.systemui.mediaprojection.appselector.MediaProjectionAppSelectorControllerTest
Test: manual check that recent tasks don't have apps from
  a profile different from the host app profile
Change-Id: I7247cbc9e45565e157ea70de77f5f7e6563723ad