Add 4 new fields to KeychainSnapshot

The fields are necessary to construct correct arguments for recovery session.
 maxAttempts
 counterId
 serverParams
 trustedHardwarePublicKey

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: If8fbc2e0a313d4367712e3598925eab0fb334258