Fix rubocop issue active_record_subscriber_shared_examples

Ran rubocop -a after removing the disable.

spec/support/shared_examples/metrics/active_record_subscriber_shared_examples.rb

@@ -19,9 +19,8 @@ RSpec.shared_examples 'store ActiveRecord info in RequestStore' do |db_role|
       Gitlab::WithRequestStore.with_request_store do
         subscriber.sql(event)
 
-        # rubocop:disable Style/ConditionalAssignment
-        if db_role == :primary
-          expected = expected_payload_defaults.merge({
+        expected = if db_role == :primary
+                     expected_payload_defaults.merge({
                        db_count: record_query ? 1 : 0,
                        db_write_count: record_write_query ? 1 : 0,
                        db_cached_count: record_cached_query ? 1 : 0,
@@ -37,7 +36,7 @@ RSpec.shared_examples 'store ActiveRecord info in RequestStore' do |db_role|
                        "db_primary_#{db_config_name}_wal_cached_count": record_wal_query && record_cached_query ? 1 : 0
                      })
                    elsif db_role == :replica
-          expected = expected_payload_defaults.merge({
+                     expected_payload_defaults.merge({
                        db_count: record_query ? 1 : 0,
                        db_write_count: record_write_query ? 1 : 0,
                        db_cached_count: record_cached_query ? 1 : 0,
@@ -53,13 +52,12 @@ RSpec.shared_examples 'store ActiveRecord info in RequestStore' do |db_role|
                        "db_replica_#{db_config_name}_wal_cached_count": record_wal_query && record_cached_query ? 1 : 0
                      })
                    else
-          expected = {
+                     {
                        db_count: record_query ? 1 : 0,
                        db_write_count: record_write_query ? 1 : 0,
                        db_cached_count: record_cached_query ? 1 : 0
                      }
                    end
-        # rubocop:enable Style/ConditionalAssignment
 
         expect(described_class.db_counter_payload).to eq(expected)
       end