Fix 'always' preferred app assignment

In the case when some possible resolutions of a given intent are at
different priorities (typically when they're intended as fallbacks when
no "normal" handler for the intent exists) the check for "is this the
same set of possible handlers that we saw last time?" was broken.  We
now ignore resolver priority entirely in that check: match set comparison
should be orthogonal to prioritization within the set, and indeed the
priority is dealt with separately in any event.

Bug 19011225

Change-Id: I3c1658442cc88b1f4a5c5f2fe9f64472799e156c