Add `checksum` sha_attribute into Vulnerabilities::Remediation model

ee/app/models/vulnerabilities/remediation.rb

@@ -3,9 +3,12 @@
 module Vulnerabilities
   class Remediation < ApplicationRecord
     include FileStoreMounter
+    include ShaAttribute
 
     self.table_name = 'vulnerability_remediations'
 
+    sha_attribute :checksum
+
     has_many :finding_remediations, class_name: 'Vulnerabilities::FindingRemediation', inverse_of: :remediation, foreign_key: 'vulnerability_remediation_id'
     has_many :findings, through: :finding_remediations
 
@@ -13,5 +16,6 @@ module Vulnerabilities
 
     validates :summary, presence: true, length: { maximum: 200 }
     validates :file, presence: true
+    validates :checksum, presence: true
   end
 end

ee/spec/models/vulnerabilities/remediation_spec.rb

@@ -8,5 +8,6 @@ RSpec.describe Vulnerabilities::Remediation do
 
   it { is_expected.to validate_presence_of(:summary) }
   it { is_expected.to validate_presence_of(:file) }
+  it { is_expected.to validate_presence_of(:checksum) }
   it { is_expected.to validate_length_of(:summary).is_at_most(200) }
 end