increased CAN rx thread size to avoid freezing problems. Decreased defau...

...lt timeout from 10 to 2 seconds.

@jcappaert noticed that during a can tx timeout (Note: this only occurs when there are electrical errors on the bus, NOT when the node it is trying to communicate is not available), the system would freeze. I tracked this down to a memory issue, and increased the CAN RX thread's allocated size to alleviate issues. Also, per @jcappaert's request, decreased the default timeout from 10000 to 2000ms, because you would rightly not encounter a normal response  that took 2 seconds or longer. 

@jtrutna @bordicon @mconst-nanosatisfi @ebobby