Fix Keystore 2.0 related bug in gatekeeperd.

Test: atest android.keystore.cts.CipherTest#testEmptyPlaintextEncryptsAndDecryptsWhenUnlockedRequired
Change-Id: Iec3d8aa34db040d5d4a418307020019ca32b0ffb
diff --git a/gatekeeperd/gatekeeperd.cpp b/gatekeeperd/gatekeeperd.cpp
index 941f8c2..781b4af 100644
--- a/gatekeeperd/gatekeeperd.cpp
+++ b/gatekeeperd/gatekeeperd.cpp
@@ -327,7 +327,6 @@
                         LOG(ERROR) << "Failure in sending AuthToken to AuthorizationService.";
                         return GK_ERROR;
                     }
-                    AIBinder_decStrong(authzAIBinder);
                 }
                 sp<IServiceManager> sm = defaultServiceManager();