Make SW keymaster security level configurable

This CL enables the pure software keymaster implementation to have a
configurable security level, for testing, so we can use it to test
Strongbox features.

Test:  VtsHalKeymasterV4_0TargetTest (on emulator)
Change-Id: I017fd81df3dc14ac5c11943241b63ff3291a92e6
Merged-In: I1b012dcd359e294dad7771c7a91e36270d9a0289
Merged-In: I10515d77310b4d2fd2922e1083df19269f199f33
Merged-In: Ibe86062000373bb71244256c4ebd81ad42bfb0da
4 files changed