Make KmVersion modifiable by subclasses.

Ignore-AOSP-First: No merge path from AOSP
Bug: 177729159
Test: VtsAidlKeyMintTargetTest
Merged-In: I395a1de3779500d526ea4c0d930b66979fca70bc
Change-Id: I395a1de3779500d526ea4c0d930b66979fca70bc
1 file changed