Prepare PropertyInvalidatedCache for SystemApi

Bug: 152453213
Tag: #refactor

This commit prepares PropertyInvalidatedCache to function as a system
api.  Specifically, the methods recompute() and bypass() which may be
overridden by clients are now public (instead of protected).  This
forces an update to all existing clients, to accommodate the change in
method visibility.

Two small changes have been made as cleanup:

 1. The awkwardly named debugCompareQueryResults() is now
    resultEquals(), which is more or less consistent with how other
    equality tests are named in Android.  This name change affects two
    clients.

 2. PackageManager has changed to use resultEquals() instead of
    maybeCheckConsistency().  This provides a simpler and more
    consistent use of the APIs.  maybeCheckConsistency() has been made
    private.

Test: atest PropertyInvalidatedCacheTests

Change-Id: I4110f8e887a4fd8c784141e8892557a9d1b80a94