Filter out more things in install shim
Filter out more things in install shim

This reduces tens of MB of install shim.

BUG=chrome-os-partner:16712
TEST=Build install shim and install with it.

Change-Id: Ic7fab3c6e26d9b78f5181c4f10181217c1c2697a
Signed-off-by: Vic Yang <5fd92abeee651458f98e2856f4f200ee971cee4d@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/39534
Reviewed-by: Tom Wai-Hong Tam <04b587fdf5845741a0c5a8b9cd59ca72d73ef8fc@chromium.org>

BugRoger/scripts,trnubo/scripts,marineam/coreos-scripts,endocode/scripts,mischief/scripts,trnubo/scripts,andrejro/coreos--scripts,mjg59/scripts,fivethreeo/scripts,zhang0137/scripts,coreos/scripts,coreos/scripts,glevand/coreos--scripts,glevand/coreos--scripts,nicescale/scripts,BugRoger/scripts,vmware/coreos-scripts,sigma/coreos-scripts,zhang0137/scripts,bcwaldon/coreos-scripts,mjg59/scripts,zhang0137/scripts,mischief/scripts,crawford/scripts,nicescale/scripts,fivethreeo/scripts,vmware/coreos-scripts,crawford/scripts,sigma/coreos-scripts,marineam/coreos-scripts,andrejro/coreos--scripts,marineam/coreos-scripts,endocode/scripts,gtank/scripts,gtank/scripts,sigma/coreos-scripts,fivethreeo/scripts,smilart/scripts,gtank/scripts,smilart/scripts,mischief/scripts,nicescale/scripts,mjg59/scripts,crawford/scripts,bcwaldon/coreos-scripts,smilart/scripts,vmware/coreos-scripts,trnubo/scripts,BugRoger/scripts,bcwaldon/coreos-scripts,andrejro/coreos--scripts,endocode/scripts