Call dmabuf_dump tool in dumpstate

This tool will dump shared buffer information on bug reports. Since it
is being rolled out on specific products, look for the binary in
/product/bin and execute it if found.

Bug: 63860998

Change-Id: If6e4ff48d3bc62e1fa7a88f16cc6ab0d5b05176f
Signed-off-by: Erick Reyes <erickreyes@google.com>