Throw exception when gatekeeper fails

This is a non-recoverable system internal error and let's make the
failure loud and clear.

Bug: 148159520
Test: atest com.android.server.locksettings
Change-Id: I38737113d9d06862077b873548dbdfe025578cdd

services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java

@@ -590,8 +590,8 @@ public class SyntheticPasswordManager {
             throw new IllegalStateException("Failed to create new SID for user", e);
         }
         if (response.getResponseCode() != GateKeeperResponse.RESPONSE_OK) {
-            Slog.e(TAG, "Fail to create new SID for user " + userId);
-            return;
+            throw new IllegalStateException("Fail to create new SID for user " + userId
+                    + " response: " + response.getResponseCode());
         }
         saveSyntheticPasswordHandle(response.getPayload(), userId);
     }