Use better names for associated classes of RecoveryManager

I will also rename RecoveryManager to RecoveryController -- in a separate CL,
as this one is already becoming too large.

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

Change-Id: I2fb4e1f55fb50d95f15c230783c3d289dd71f7f3