Improved the experience with bypass and dynamic privacy

The user can now use the expand buttons and also clear
all is invisible while locked down.
The can also drag down normally to reveal the
contents of a notification.
Also, the section clear button is also properly updated
once dynamic privacy changes.

Fixes: 138671060
Fixes: 138669307
Test: drag down with notif hidden and bypass on on a sensitive notification
Change-Id: I8743400d0b46583802a8663f6723dfa6beee95c9