Merge "[DO NOT MERGE] Updating Platform Security String to 2017-12-01 on mnc-dev. Bug: 67774760" into mnc-dev am: 948d98b31a am: c4a501ce0f am: 0ef4e8a5e1 am: 960319ef76  -s ours
am: a417f92e6d

Change-Id: Ibd7aa853631df426c44cfaf9f125c54778843151