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

vold.te

@@ -17,7 +17,7 @@ allow vold sdcard_type:dir create_dir_perms;
 allow vold tmpfs:filesystem { mount unmount };
 allow vold tmpfs:dir create_dir_perms;
 allow vold tmpfs:dir mounton;
-allow vold self:capability { net_admin dac_override mknod sys_admin chown fowner };
+allow vold self:capability { net_admin dac_override mknod sys_admin chown fowner fsetid };
 allow vold self:netlink_kobject_uevent_socket *;
 allow vold app_data_file:dir search;
 allow vold app_data_file:file rw_file_perms;