1. We don't parse PAD options properly, leading in failure to parse packets sent by DHCP servers that put the end of options marker after pad options and at an odd offset. 2. We get the DhcpResults vendorInfo from the wrong option type (60 instead of 43). Fix these and add unit tests for the offer packets sent by a few different DHCP servers. Bug: 21955617 Bug: 22281295 Change-Id: I5d13f1a6a3ff0b53112f18f3db8792fa32ad2da3