Report KeyStore/KeyMint error messages via public API.
This lets developers find out:
* Whether an error is transient or not.
* Whether a failure is due to a system error
(system configuration/state/capabilities), or a key-related error.
* Whether user authentication is required to use the key.
Test: atest CtsKeystorePerformanceTestCases CtsKeystoreTestCases
Bug: 197890905
Change-Id: I776d9e9cc01a9dc3542a63000ee0709847760963
The code in question talks to KeyStore which returns error codes
which are a mix of keystore and keymaster error codes. To better
match the layering of KeyStore on top of keystore and keymaster,
this CL renames KeymasterException into KeyStoreException. It also
adds human-readable error messages to exceptions raised by keystore
rather than keymaster (e.g., key not found).
Bug: 18088752
Change-Id: I4cd1235e16518c9f2e8c5557a457774c6e687b88
