Small refactor to clarify auth token ownership.

The Operation interface confused me.  It looked like it was holding a
pointer to an auth token from the AuthTokenTable.  In fact it made a
copy, but that wasn't clear from the interface.  Ths CL changes
Operation::setOperationAuthtoken to take the token by value, making
clear that it copies (unless std::move is used).

Test: runtest --path cts/tests/tests/keystore/src/android/keystore/cts
Change-Id: I1d1b6983f421f5be9f56c60aaf56dda8fc4aa207
diff --git a/keystore/operation.h b/keystore/operation.h
index e69b43a..9249437 100644
--- a/keystore/operation.h
+++ b/keystore/operation.h
@@ -57,7 +57,7 @@
     bool getOperationAuthToken(const android::sp<android::IBinder>& token,
                                const HardwareAuthToken** outToken);
     bool setOperationAuthToken(const android::sp<android::IBinder>& token,
-                               const HardwareAuthToken* authToken);
+                               HardwareAuthToken authToken);
     android::sp<android::IBinder> getOldestPruneableOperation();
     std::vector<android::sp<android::IBinder>>
     getOperationsForToken(const android::sp<android::IBinder>& appToken);