Add CertPath to KeyChainSnapshot and startRecoverySession

CertPath will include a cert of the trusted hardware and necessary
intermediate certificates.

Bug: 73784851
Change-Id: Ic70616b8f119891a82402b91035456e404c5f6de
Test: adb shell am instrument -w -e package \
com.android.server.locksettings.recoverablekeystore \
com.android.frameworks.servicestests/android.support.test.runner.AndroidJUnitRunner