Use rootAlias to index chosen cert and its version.

Added new column  to store active alias for given recovery agent.
Added new table with chosen certififcate and cert list serial number indexed
by recovery agent and root of trust.

Bug: 76433465
Test: adb shell am instrument -w -e package
com.android.server.locksettings.recoverablekeystore
com.android.frameworks.servicestests/android.support.test.runner.AndroidJUnitRunner

Change-Id: Iae8b84312805400bf1acd4db242efeb6d167c000