Bulk apply PendingIntent.FLAG_MUTABLE_UNAUDITED.

We've been working hard to require PendingIntents explicitly declare
if they allow their contents to be mutated or not, and to finish
landing that work this change applies the new FLAG_MUTABLE_UNAUDITED
flag to all remaining code locations until they can be manually
inspected.

Bug: 160794467
Test: manual
Change-Id: I8d7ec64ac89755c14b5959bb6ef0bce203c92bf0