Fix allocator::map template argument ordering

allocator::map reversed Key and T from std::map

Bug: 27208635
Change-Id: I4e4db704539d01b060cb948aa573cb674da48c7d
(cherry picked from commit 4c5bccdd863f5369282771a156218041862cc9f1)
diff --git a/libmemunreachable/ThreadCapture.cpp b/libmemunreachable/ThreadCapture.cpp
index 6357840..e8a8392 100644
--- a/libmemunreachable/ThreadCapture.cpp
+++ b/libmemunreachable/ThreadCapture.cpp
@@ -86,7 +86,7 @@
   void PtraceDetach(pid_t tid, unsigned int signal);
   bool PtraceThreadInfo(pid_t tid, ThreadInfo& thread_info);
 
-  allocator::map<unsigned int, pid_t> captured_threads_;
+  allocator::map<pid_t, unsigned int> captured_threads_;
   Allocator<ThreadCaptureImpl> allocator_;
   pid_t pid_;
   std::function<void(pid_t)> inject_test_func_;