Sanitize given scan types before querying the security_scans

After migrating the Rails version 6.1.4.1, we've found a regression in
one of our model scopes that was causing exceptions if an invalid enum
key is provided. This commit fixes that regression.

Changelog: fixed

ee/app/models/security/scan.rb

@@ -27,7 +27,7 @@ module Security
       cluster_image_scanning: 8
     }
 
-    scope :by_scan_types, -> (scan_types) { where(scan_type: scan_types) }
+    scope :by_scan_types, -> (scan_types) { where(scan_type: sanitize_scan_types(scan_types)) }
 
     scope :scoped_project, -> { where('security_scans.project_id = projects.id') }
 
@@ -50,6 +50,10 @@ module Security
 
     before_save :ensure_project_id_pipeline_id
 
+    def self.sanitize_scan_types(given_types)
+      scan_types.keys & Array(given_types).map(&:to_s)
+    end
+
     def has_errors?
       processing_errors.present?
     end

ee/lib/ee/gitlab/usage_data.rb

@@ -414,9 +414,9 @@ module EE
 
           start_id, finish_id = min_max_security_scan_id(time_period)
 
-          ::Security::Scan.scan_types.each do |name, scan_type|
+          ::Security::Scan.scan_types.each do |name, _|
             relation = ::Security::Scan
-                         .by_scan_types(scan_type)
+                         .by_scan_types(name)
                          .where(time_period)
 
             metric_name = "#{name}_pipeline"

ee/spec/models/security/scan_spec.rb

@@ -70,13 +70,20 @@ RSpec.describe Security::Scan do
   end
 
   describe '.by_scan_types' do
-    let!(:sast_scan) { create(:security_scan, scan_type: :sast) }
-    let!(:dast_scan) { create(:security_scan, scan_type: :dast) }
+    let_it_be(:sast_scan) { create(:security_scan, scan_type: :sast) }
+    let_it_be(:dast_scan) { create(:security_scan, scan_type: :dast) }
+
     let(:expected_scans) { [sast_scan] }
 
     subject { described_class.by_scan_types(:sast) }
 
     it { is_expected.to match_array(expected_scans) }
+
+    context 'when an invalid enum value is given' do
+      subject { described_class.by_scan_types([:sast, :generic]) }
+
+      it { is_expected.to match_array(expected_scans) }
+    end
   end
 
   describe '.latest_successful_by_build' do