Add tests for KeySyncUtils now that SecureBox is available

SecureBox is to be merged before this.

Test: adb shell am instrument -w -e package com.android.server.locksettings.recoverablekeystore com.android.frameworks.servicestests/android.support.test.runner.AndroidJUnitRunner
Change-Id: I40f783c165faa595c8913ff073915726ae71524d
2 files changed