Merge tag 'android-6.0.0_r26' into HEAD

Android 6.0.0 release 26

* tag 'android-6.0.0_r26':
  extensions: libxt_socket: add --restore-skmark option
  xt_socket: add --nowildcard flag

Change-Id: I40423d9feace8d9ac76bbdc1b288520fd58127e6