binderRpcTest: assert on wait_for timeout

Use a version of wait_for that won't return for spurious wakeups.

Test: atest binderRpcTest
Bug: NA
Change-Id: I42ad6eb66d36759193980e1532ac9e6ec7565435
diff --git a/libs/binder/tests/binderRpcTest.cpp b/libs/binder/tests/binderRpcTest.cpp
index 501a604..87c204f 100644
--- a/libs/binder/tests/binderRpcTest.cpp
+++ b/libs/binder/tests/binderRpcTest.cpp
@@ -1062,10 +1062,7 @@
     }
 
     std::unique_lock<std::mutex> lock(dr->mMtx);
-    if (!dr->dead) {
-        EXPECT_EQ(std::cv_status::no_timeout, dr->mCv.wait_for(lock, 1000ms));
-    }
-    EXPECT_TRUE(dr->dead) << "Failed to receive the death notification.";
+    ASSERT_TRUE(dr->mCv.wait_for(lock, 1000ms, [&]() { return dr->dead; }));
 
     // need to wait for the session to shutdown so we don't "Leak session"
     EXPECT_TRUE(proc.proc.sessions.at(0).session->shutdownAndWait(true));