Fixed the concurrent modified exception

The static map could be accessed by multiple threads. Changed
to a thread-safe map.

Fix: 197776892
Test: Manual
Merged-In: Ife1624c2f8fb02421ffeebfd6749d12bff7d8d68
Change-Id: Ife1624c2f8fb02421ffeebfd6749d12bff7d8d68
(cherry picked from commit b59e2ea4)