keystore: add API to query storage type

Add an API to query the HAL to see what kind of storage it reports the
device is.

(cherry picked from commit 8ddf35a6e1fd80a7d0685041d2bfc77078277c9d)

Change-Id: I04a9421053a0b8bbe4f0dd73fefdfdbe4ab4add9
3 files changed
tree: 92431a66dcb87e3f6ca5582a85957069e05e27f6
  1. keystore/
  2. keystore-engine/
  3. softkeymaster/