Missing parts:
1) Whitelist locksettingsservice to use grant API.
2) Probably have similar update for recovered keys - they will live in
system service and RecoveryAgent will use getKey() method to access
them.
3) ApplicationKeyStorageTest
Bug: 66499222
Test: adb shell am instrument -w -e package \
com.android.server.locksettings.recoverablekeystore \
com.android.frameworks.servicestests/android.support.test.runner.AndroidJUnitRunner
Change-Id: I584b89e3f777bed679b2eb5173750f3f1dee3635