libbinder fuzzer driver: clear calling identity

This gets set in thread local state.

Bug: N/A
Test: servicemanager fuzzer will test past SELinux checks (gives
  even mix of this and specifically set UID)
Change-Id: I42d39eecd3ceca6e702dec1df725e5f7e83b6a26
diff --git a/libs/binder/tests/parcel_fuzzer/libbinder_driver.cpp b/libs/binder/tests/parcel_fuzzer/libbinder_driver.cpp
index 24a9345..5905f7b 100644
--- a/libs/binder/tests/parcel_fuzzer/libbinder_driver.cpp
+++ b/libs/binder/tests/parcel_fuzzer/libbinder_driver.cpp
@@ -33,6 +33,10 @@
             .extraFds = {},
     };
 
+    // always refresh the calling identity, because we sometimes set it below, but also,
+    // the code we're fuzzing might reset it
+    IPCThreadState::self()->clearCallingIdentity();
+
     // Always take so that a perturbation of just the one ConsumeBool byte will always
     // take the same path, but with a different UID. Without this, the fuzzer needs to
     // guess both the change in value and the shift at the same time.