Do not include internal GTest header.

Only the headers gtest.h and gtest-spi.h are public.  This
inclusion is causing a build break when upgrading googletest
to version 1.13.0.

Bug: 271622675
Test: local build, presubmit
Change-Id: I698e4d4464c131e9dad73a23a6f65908a07e9f60
diff --git a/audio/aidl/vts/TestUtils.h b/audio/aidl/vts/TestUtils.h
index 4c1d42c..72ca56f 100644
--- a/audio/aidl/vts/TestUtils.h
+++ b/audio/aidl/vts/TestUtils.h
@@ -21,7 +21,7 @@
 #include <iostream>
 
 #include <android/binder_auto_utils.h>
-#include <gtest/gtest_pred_impl.h>
+#include <gtest/gtest.h>
 
 namespace android::hardware::audio::common::testing {