Fix assumption about number of keys provisioned

The server was recently changed to require only 12 keys, not 20. Some
tests were depending on 20 keys to be provisioned. Fix this assumption:
1. Don't make any assumptions about the number of keys provisioned
2. Don't consume keys in provisionThenExpireThenProvisionAgain, just
   update expiry. This should prevent the server from re-provisioning
   keys (which throws off the test logic)

Test: RkpdAppHostTests
Bug: 279737866
(cherry picked from https://android-review.googlesource.com/q/commit:b5c22f11a2c4f42c94e63ffa17d3c6007bfd0151)
Merged-In: Id6c4ae1f9adce1379e6c2baa6a046b9143fa7b23
Change-Id: Id6c4ae1f9adce1379e6c2baa6a046b9143fa7b23
3 files changed
tree: 05246fe1a5f8901eefd04384a8fc410e72224ef2
  1. apex/
  2. app/
  3. system-server/
  4. OWNERS
  5. PREUPLOAD.cfg