Remove db layer hard-code permission checks for network_get_all_by_host
Remove db layer hard-code permission checks for network_get_all_by_host

This patches removes db layer hard-code permission checks for
network_get_all_by_host.

It is called by the follow function:
  1. init_host, context is elevated.
  2. _periodic_update_dns, is periodic task
  3. update_dns it is call by
     network.manager.allocate_for_instance and
     nova.network.manager.add_fixed_ip_to_instance
     this is fixed by https://review.openstack.org/#/c/150687

Partially implements bp nova-api-policy-final-part

Change-Id: I5c503005598d9299db330463b8ffaeb383377b37

noironetworks/nova,edulramirez/nova,gooddata/openstack-nova,vmturbo/nova,apporc/nova,klmitch/nova,hanlind/nova,CEG-FYP-OpenStack/scheduler,belmiromoreira/nova,LoHChina/nova,jianghuaw/nova,belmiromoreira/nova,nikesh-mahalka/nova,ted-gould/nova,vmturbo/nova,watonyweng/nova,zaina/nova,rajalokan/nova,tangfeixiong/nova,openstack/nova,NeCTAR-RC/nova,takeshineshiro/nova,takeshineshiro/nova,isyippee/nova,Francis-Liu/animated-broccoli,akash1808/nova,sebrandon1/nova,bgxavier/nova,j-carpentier/nova,cernops/nova,CloudServer/nova,kimjaejoong/nova,rajalokan/nova,nikesh-mahalka/nova,JianyuWang/nova,mikalstill/nova,double12gzh/nova,openstack/nova,cernops/nova,Tehsmash/nova,tealover/nova,zzicewind/nova,cernops/nova,mahak/nova,MountainWei/nova,jeffrey4l/nova,klmitch/nova,Juniper/nova,sebrandon1/nova,yatinkumbhare/openstack-nova,felixma/nova,gooddata/openstack-nova,alvarolopez/nova,sebrandon1/nova,scripnichenko/nova,barnsnake351/nova,dims/nova,cyx1231st/nova,tudorvio/nova,alvarolopez/nova,akash1808/nova_test_latest,Stavitsky/nova,mandeepdhami/nova,gooddata/openstack-nova,mmnelemane/nova,whitepages/nova,JioCloud/nova_test_latest,fnordahl/nova,raildo/nova,iuliat/nova,varunarya10/nova_test_latest,cyx1231st/nova,hanlind/nova,rajalokan/nova,yosshy/nova,shail2810/nova,JioCloud/nova,mahak/nova,Juniper/nova,double12gzh/nova,ruslanloman/nova,klmitch/nova,eonpatapon/nova,vmturbo/nova,barnsnake351/nova,JianyuWang/nova,whitepages/nova,fnordahl/nova,JioCloud/nova_test_latest,yosshy/nova,apporc/nova,Tehsmash/nova,watonyweng/nova,phenoxim/nova,varunarya10/nova_test_latest,BeyondTheClouds/nova,Juniper/nova,cloudbase/nova,mmnelemane/nova,TwinkleChawla/nova,CEG-FYP-OpenStack/scheduler,akash1808/nova,devendermishrajio/nova_test_latest,felixma/nova,ted-gould/nova,jianghuaw/nova,CCI-MOC/nova,LoHChina/nova,hanlind/nova,cloudbase/nova,JioCloud/nova,zhimin711/nova,zhimin711/nova,akash1808/nova_test_latest,zaina/nova,thomasem/nova,mahak/nova,bigswitch/nova,NeCTAR-RC/nova,tealover/nova,devendermishrajio/nova,BeyondTheClouds/nova,Stavitsky/nova,eonpatapon/nova,klmitch/nova,bigswitch/nova,rahulunair/nova,MountainWei/nova,jianghuaw/nova,isyippee/nova,tangfeixiong/nova,cloudbase/nova,mikalstill/nova,raildo/nova,alaski/nova,j-carpentier/nova,CCI-MOC/nova,jeffrey4l/nova,noironetworks/nova,openstack/nova,scripnichenko/nova,devendermishrajio/nova_test_latest,thomasem/nova,Francis-Liu/animated-broccoli,gooddata/openstack-nova,yatinkumbhare/openstack-nova,iuliat/nova,zzicewind/nova,alaski/nova,tudorvio/nova,adelina-t/nova,vmturbo/nova,devendermishrajio/nova,rajalokan/nova,mandeepdhami/nova,Juniper/nova,adelina-t/nova,dims/nova,BeyondTheClouds/nova,CloudServer/nova,shail2810/nova,jianghuaw/nova,rahulunair/nova,edulramirez/nova,phenoxim/nova,mikalstill/nova,rahulunair/nova,TwinkleChawla/nova,bgxavier/nova,kimjaejoong/nova,ruslanloman/nova