Provide means for system_server to query ION memory usage. The new API allows to get total size of ION heaps, pools and part of ION heaps that is mapped into user space. Bug: 138148041 Test: dumpsys meminfo Change-Id: I6d76d534bbab5ee1646e8e3e3fe5210dcf76bc23 Signed-off-by: Suren Baghdasaryan <surenb@google.com>