Grant fsetid Linux capability to vold.

This fixes the issue where paid apps failed to install via Google
Play with "Package file has a bad manifest" error. The issue appears
to be caused by vold being prevented by SELinux policy from setting
the setgid bit on the ASEC container directory into which the APK is
decrypted. As a result, the APK is not readable to PackageParser.

Bug: 9736808
Change-Id: I07546a9f9caac3de8b720499bd1bf1604edea0fe