Prepare KeyStore RecoveryController API for review.

- set/get recovery status simplification
- adding account to WrappedKey
- moving recovery methods to the Session class.

There are small cosmetical changes to .aidl which don't affect
implementation logic.

Bug: 72299798
Test: adb shell am instrument -w -e package
com.android.server.locksettings.recoverablekeystore
com.android.frameworks.servicestests/android.support.test.runner.AndroidJUnitRunner

Change-Id: I9efaa4cde42cf778bb97ed13f62750a65d8c6cb5