Fix the last temp file creation problem in unittest

Use MakeTempFile instead of using an absolute path in stream_unittest.cc

Bug: 78016597
Test: unittests
Change-Id: I82f05971c032bae5ca7c1f4c304ef7ff32751bf3
diff --git a/src/stream_unittest.cc b/src/stream_unittest.cc
index 573b539..30813ee 100644
--- a/src/stream_unittest.cc
+++ b/src/stream_unittest.cc
@@ -175,7 +175,8 @@
 }
 
 TEST_F(StreamTest, FileStreamTest) {
-  string filepath("/tmp/test_filepath");
+  string filepath;
+  ASSERT_TRUE(MakeTempFile(&filepath, nullptr));
   ScopedPathUnlinker scoped_unlinker(filepath);
   ASSERT_FALSE(FileStream::Open(filepath, false, false));