dumpstate: Kill vendor dumpstate HAL and grab partial dump in timeout

dumpstate_board should not block forever but it is also a valuable
source for debugging system problems. In timeout case, we should kill
dumpstate HAL in case it hangs (e.g. cat from a pipe or so), so the
following calls can be served by HAL service.

Bug: 77489941
Test: simulate delay in dumpstate HAL and get BR, see partial content
    from dumpstate_board.tx and below log from dumpstate_log.txt
    dumpstateBoard timed out after 10s, killing dumpstate vendor HAL
    dumpstateBoard failed: Status(EX_TRANSACTION_FAILED): 'DEAD_OBJECT: '
Change-Id: Iadfd0c234c26714b6a2f1aa2941a85d4e01d2cbc