Support upgrade key for software-emulated keys.

Currently software-emulated keys do not have any update mechanism. Any
software key that is created in previous versions cannot be used once
the device is upgraded. With this change, keys now can be upgraded and
used by the latest keystore.

Change-Id: Ic791baeedd7775df7eafca405440e645b19ec2bc
Test: TreeHugger
Fixes: 223376764
Fixes: 249021523
Merged-In: Ic791baeedd7775df7eafca405440e645b19ec2bc
Ignore-AOSP-First: Cherry-picking to tm-qpr-dev.
1 file changed