[rkp] Generalize CBOR conversion functions for reuse am: facc2b82cf

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Virtualization/+/2775150

Change-Id: Ic62dce880c78ed1ae97596bf723d1eae1fa36140
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>