PLT-5080 (WebApp): Channel Admin permission level. (#5047)

* PLT-5080 (WebApp): Channel Admin permission level.

For channel management and channel deletion.

* Fix some incorrect showing/hiding of options.

* Remove incorrect client calls that was overwriting my channel members.

webapp/components/admin_console/policy_settings.jsx

@@ -115,6 +115,7 @@ export default class PolicySettings extends AdminSettings {
                     id='restrictPublicChannelManagement'
                     values={[
                         {value: Constants.PERMISSIONS_ALL, text: Utils.localizeMessage('admin.general.policy.permissionsAllChannel', 'All channel members')},
+                        {value: Constants.PERMISSIONS_CHANNEL_ADMIN, text: Utils.localizeMessage('admin.general.policy.permissionsChannelAdmin', 'Channel, Team and System Admins')},
                         {value: Constants.PERMISSIONS_TEAM_ADMIN, text: Utils.localizeMessage('admin.general.policy.permissionsAdmin', 'Team and System Admins')},
                         {value: Constants.PERMISSIONS_SYSTEM_ADMIN, text: Utils.localizeMessage('admin.general.policy.permissionsSystemAdmin', 'System Admins')}
                     ]}
@@ -137,6 +138,7 @@ export default class PolicySettings extends AdminSettings {
                     id='restrictPublicChannelDeletion'
                     values={[
                         {value: Constants.PERMISSIONS_ALL, text: Utils.localizeMessage('admin.general.policy.permissionsAllChannel', 'All channel members')},
+                        {value: Constants.PERMISSIONS_CHANNEL_ADMIN, text: Utils.localizeMessage('admin.general.policy.permissionsChannelAdmin', 'Channel, Team and System Admins')},
                         {value: Constants.PERMISSIONS_TEAM_ADMIN, text: Utils.localizeMessage('admin.general.policy.permissionsAdmin', 'Team and System Admins')},
                         {value: Constants.PERMISSIONS_SYSTEM_ADMIN, text: Utils.localizeMessage('admin.general.policy.permissionsSystemAdmin', 'System Admins')}
                     ]}
@@ -195,6 +197,7 @@ export default class PolicySettings extends AdminSettings {
                     id='restrictPrivateChannelManagement'
                     values={[
                         {value: Constants.PERMISSIONS_ALL, text: Utils.localizeMessage('admin.general.policy.permissionsAllChannel', 'All channel members')},
+                        {value: Constants.PERMISSIONS_CHANNEL_ADMIN, text: Utils.localizeMessage('admin.general.policy.permissionsChannelAdmin', 'Channel, Team and System Admins')},
                         {value: Constants.PERMISSIONS_TEAM_ADMIN, text: Utils.localizeMessage('admin.general.policy.permissionsAdmin', 'Team and System Admins')},
                         {value: Constants.PERMISSIONS_SYSTEM_ADMIN, text: Utils.localizeMessage('admin.general.policy.permissionsSystemAdmin', 'System Admins')}
                     ]}
@@ -217,6 +220,7 @@ export default class PolicySettings extends AdminSettings {
                     id='restrictPrivateChannelDeletion'
                     values={[
                         {value: Constants.PERMISSIONS_ALL, text: Utils.localizeMessage('admin.general.policy.permissionsAllChannel', 'All channel members')},
+                        {value: Constants.PERMISSIONS_CHANNEL_ADMIN, text: Utils.localizeMessage('admin.general.policy.permissionsChannelAdmin', 'Channel, Team and System Admins')},
                         {value: Constants.PERMISSIONS_TEAM_ADMIN, text: Utils.localizeMessage('admin.general.policy.permissionsAdmin', 'Team and System Admins')},
                         {value: Constants.PERMISSIONS_SYSTEM_ADMIN, text: Utils.localizeMessage('admin.general.policy.permissionsSystemAdmin', 'System Admins')}
                     ]}