Disable clear notifications when screenshare

When screensharing, notifications that are not dismissable should also
not be clearable

Bug: 324285161
Test: atest StackCoordinatorTest
Flag: ACONFIG com.android.server.notification.screenshare_notification_hiding TRUNKFOOD
Flag: ACONFIG com.android.systemui.screenshare_notification_hiding_bug_fix DISABLED
Change-Id: I44badef472f46b166f94e9a8e1b07f36dbbbfc3c