Description of problem:
looks like 6.3.1-2 introduced this since the test was passing in snap#1.
thus i think it got introduced by
https://bugzilla.redhat.com/show_bug.cgi?id=1563262

importing a host subscription csv causes a ISE:

hammer -v -u admin -p changeme  csv content-hosts --organization="ao936E" --file="/tmp/chs_import_ao936E.csv"

[ERROR 2018-04-09 08:30:31 API] 500 Internal Server Error
[ERROR 2018-04-09 08:30:31 Exception] Error: 500 Internal Server Error
ejrqrvfjymialarl.lab.eng.rdu2.redhat.com,ao936E,m4ZJ91,TkreoTZuhu,,Yes,,Red Hat Enterprise Linux Server,x86_64,1,500208,1,,69|Red Hat Enterprise Linux Server,"""1|SER0232US|Red Hat Satellite Employee Subscription|10843764|477931"""

Error: 500 Internal Server Error
ejrqrvfjymialarl.lab.eng.rdu2.redhat.com,ao936E,m4ZJ91,TkreoTZuhu,,Yes,,Red Hat Enterprise Linux Server,x86_64,1,500208,1,,69|Red Hat Enterprise Linux Server,"""1|SER0232US|Red Hat Satellite Employee Subscription|10843764|477931"""
[ERROR 2018-04-09 08:30:31 Exception] 

RuntimeError (500 Internal Server Error
ejrqrvfjymialarl.lab.eng.rdu2.redhat.com,ao936E,m4ZJ91,TkreoTZuhu,,Yes,,Red Hat Enterprise Linux Server,x86_64,1,500208,1,,69|Red Hat Enterprise Linux Server,"""1|SER0232US|Red Hat Satellite Employee Subscription|10843764|477931"""
):
    /opt/theforeman/tfm/root/usr/share/gems/gems/hammer_cli_csv-2.3.0/lib/hammer_cli_csv/base.rb:153:in `rescue in block (3 levels) in thread_import'
    /opt/theforeman/tfm/root/usr/share/gems/gems/hammer_cli_csv-2.3.0/lib/hammer_cli_csv/base.rb:148:in `block (3 levels) in thread_import'
    /opt/theforeman/tfm/root/usr/share/gems/gems/hammer_cli_csv-2.3.0/lib/hammer_cli_csv/base.rb:146:in `each'
    /opt/theforeman/tfm/root/usr/share/gems/gems/hammer_cli_csv-2.3.0/lib/hammer_cli_csv/base.rb:146:in `block (2 levels) in thread_import'
    /opt/theforeman/tfm/root/usr/share/gems/gems/logging-1.8.2/lib/logging/diagnostic_context.rb:323:in `block in create_with_logging_context'


The production log reveals the error:


2018-04-09 08:30:31 7ef7af6c [app] [I] Started PUT "/api/hosts/7" for 10.16.184.122 at 2018-04-09 08:30:31 -0400
2018-04-09 08:30:31 7ef7af6c [app] [I] Processing by Api::V2::HostsController#update as JSON
2018-04-09 08:30:31 7ef7af6c [app] [I]   Parameters: {"host"=>{"content_facet_attributes"=>{"lifecycle_environment_id"=>14, "content_view_id"=>11}, "subscription_facet_attributes"=>{"installed_products"=>[{"product_id"=>"69", "product_name"=>"Red Hat Enterprise Linux Server", "arch"=>"x86_64", "version"=>"Hat"}], "service_level"=>nil, "autoheal"=>true}}, "apiv"=>"v2", "id"=>"7"}
2018-04-09 08:30:31 7ef7af6c [app] [I] Current user: foreman_admin (administrator)
2018-04-09 08:30:31 7ef7af6c [app] [I] Authorized user admin(Admin User)
2018-04-09 08:30:31 7ef7af6c [app] [I] Current user: admin (administrator)
2018-04-09 08:30:31 7ef7af6c [app] [I] Expire fragment views/tabs_and_title_records-3 (0.0ms)
2018-04-09 08:30:31 7ef7af6c [app] [I] Expire fragment views/tabs_and_title_records-3 (0.1ms)
2018-04-09 08:30:31 7ef7af6c [app] [W] Action failed
 | ActiveRecord::AssociationTypeMismatch: Katello::InstalledProduct(#80842300) expected, got ActiveSupport::HashWithIndifferentAccess(#12790900)

(see attached foreman-debug tarball for the complete log)


Version-Release number of selected component (if applicable):
6.3.1-2

How reproducible:
always

Steps to Reproduce:
1. get some content hosts with subscriptions attached
2. export the subscriptions to a csv using `hammer csv content-hosts --organization="org1" --export --file="/tmp/chs_export_ao936E.csv"` and modify it slightly
3. try to import the subscrption csv file using `hammer csv content-hosts..`

(for QA: run `py.test -k test_positive_restore_content_hosts_with_modified_subscription test_subscription.py -s`)

Actual results:
 | ActiveRecord::AssociationTypeMismatch: Katello::InstalledProduct(#80842300) expected, got ActiveSupport::HashWithIndifferentAccess(#12790900)