[DO NOT MERGE] Update platform security string to 2017-10-01 in lmp-dev Bug:64896113 am: cf83f5a4f3  -s ours am: b40465ed59 am: acc7e47faa  -s ours
am: 286c80e90a

Change-Id: I7fc0c8c77629acf745ad25006e0d2369e438dbbd