Enable hidepid=2 on /proc

Add the following mount options to the /proc filesystem:


This change blocks /proc access unless you're in group 3009

Please see
for documentation on the hidepid option.

hidepid=2 is preferred over hidepid=1 since it leaks less information
and doesn't generate SELinux ptrace denials when trying to access
/proc without being in the proper group.

Add AID_READPROC to processes which need to access /proc entries for
other UIDs.

Bug: 23310674
Change-Id: I22bb55ff7b80ff722945e224845215196f09dafa
9 files changed