Merge branch '330648-email-specific-user-in-escalation-policy' into 'master'

...n_policies/components/add_edit_escalation_policy_form.vue

..._policies/components/add_edit_escalation_policy_modal.vue

...ipts/escalation_policies/components/escalation_policy.vue

...cripts/escalation_policies/components/escalation_rule.vue

...avascripts/escalation_policies/components/user_select.vue

ee/app/assets/javascripts/escalation_policies/constants.js

...cies/graphql/fragments/escalation_policy.fragment.graphql

ee/app/assets/javascripts/escalation_policies/utils.js

...ion_policies/__snapshots__/escalation_policy_spec.js.snap

...calation_policies/add_edit_escalation_policy_form_spec.js

...alation_policies/add_edit_escalation_policy_modal_spec.js

ee/spec/frontend/escalation_policies/escalation_rule_spec.js

ee/spec/frontend/escalation_policies/mocks/apollo_mock.js

ee/spec/frontend/escalation_policies/mocks/mockPolicies.json

ee/spec/frontend/escalation_policies/user_select_spec.js

ee/spec/frontend/escalation_policies/utils_spec.js

locale/gitlab.pot