ART: Update Monitor::Wait so it releases monitor_lock_ before throwing an exception

Thread should release monitor_lock_ Mutex (which guards shared structures behind Java monitor)
in Monitor::Wait before throwing any exception. Otherwise the thread may be suspended by GC
during that time still holding the lock. This may cause deadlock during GC in case
some other thread needs to acquire the monitor_lock_. The other thread can't be suspended
by GC then waiting for exclusive lock and "thread suspend timeout" occurs.

Change-Id: Id02f45052e1cfc01e676a43434125817564d7874
Signed-off-by: Elena Sayapina <elena.v.sayapina@intel.com>