Only autoVerify at install for new hosts

Re-run app link verification at update time only when the set of hosts
has expanded.  Intentionally revoke verify history when an app stops
using autoVerify, as a one-time measure to place it back into the
non-autoverify model for tracking the user's launch preferences.  If the
app starts using autoVerify again later, it behaves identically to an
app that has never done so before.

In the included AutoVerify test apks (all the same package name):

  app1 recognizes 1 host
  app2 recognizes the same host plus a different wildcard
  app3 has the same hosts as app1 but does not autoVerify
  app4 has the same hosts as app2 but does not autoVerify

Bug: 151475497
Test: install AutoVerify app1, set to 'always', install app2, observe
that it is demoted out of always

Test: install app1 apk, set 'always', install app1 again, observe that
no verification run is performed

Test: install app2 apk, set 'always', install app1, observe that
no verification run is performed

Test: install app1 apk, verify still undefined/ask, install app1 again,
observe that a verification is performed

Test: install app2 apk, set 'always', install app1, observe that
no verification run is performed, install app2 again, observe that it is
reverified (and demoted out of always when verification fails)

Test: install app1 apk, set 'always', install app3 apk, observe that no
verification is performed & it remains in always

Test: install app1 apk, set 'always', install app4 apk, observe that no
verification is performed but it is demoted out of always

Change-Id: I200d85085ce79842a3ed39377d1f75ec381c8991