Big RecoverableKeyStoreLoader refactoring.

The change is based on API review.
1) package and class names update
2) Builders for Parcelables.
3) Use Constant for RECOVER_KEYSTORE permission defined in
android.Manifest.

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: I49f80acbb6dc0eb6d049e18e8cb0d1aa326dadb2