Multi-threaded keystore

This patches changes the keystore to use the asychronous api model for
begin, update, finish, and abort.

Also removes unused class KeystoreArguments (aidl and implementation).

Test: Keystore CTS tests
Bug: 111443219

Change-Id: Icc6def9ff6dbe32193272d7d015079a006ebc430
diff --git a/keystore/keystore_utils.cpp b/keystore/keystore_utils.cpp
index 71e8ed2..78056d6 100644
--- a/keystore/keystore_utils.cpp
+++ b/keystore/keystore_utils.cpp
@@ -107,8 +107,7 @@
 namespace keystore {
 
 hidl_vec<uint8_t> blob2hidlVec(const Blob& blob) {
-    hidl_vec<uint8_t> result;
-    result.setToExternal(const_cast<uint8_t*>(blob.getValue()), blob.getLength());
+    hidl_vec<uint8_t> result(blob.getValue(), blob.getValue() + blob.getLength());
     return result;
 }