Fix JDWP event races

Fix a race where the JDWP connection could be closed before the VM_DEATH event
is sent during runtime shutdown.

Fix potential race where we could wait forever for the JDWP thread to establish
connection.

Bug: 16720689

(cherry picked from commit d8b3537b89fa68599534a65afc3b272639cd4a75)

Change-Id: I4b8996ade6a38fa8f7f23c3000b7184b162907d7
2 files changed