"shamu" for Nexus 6　7.1.1 (N6F27C, May 2017)
https://developers.google.com/android/images#shamu
https://developers.google.com/android/ota#shamu
Android Security Bulletin?May 2017
https://source.android.com/security/bulletin/2017-05-01

7.0.0のupdateが無くなって7.1.1のみ