MM-58092 Add feature flag and setting for client performance metrics (#26942)

* MM-58092 Add feature flag and setting for client performance metrics

* Fix incorrect field name

webapp/channels/src/components/admin_console/admin_definition.tsx

@@ -1788,6 +1788,28 @@ const AdminDefinition: AdminDefinitionType = {
                             },
                             isDisabled: it.not(it.userHasWritePermissionOnResource(RESOURCE_KEYS.ENVIRONMENT.PERFORMANCE_MONITORING)),
                         },
+                        {
+                            type: 'bool',
+                            key: 'MetricsSettings.EnableClientMetrics',
+                            label: defineMessage({id: 'admin.metrics.enableClientMetricsTitle', defaultMessage: 'Enable Client Performance Monitoring:'}),
+                            help_text: defineMessage({id: 'admin.metrics.enableClientMetricsDescription', defaultMessage: 'When true, Mattermost will enable performance monitoring collection for web and desktop app users. Please see <link>documentation</link> to learn more about configuring performance monitoring for Mattermost.'}),
+                            help_text_markdown: false,
+                            help_text_values: {
+                                link: (msg: string) => (
+                                    <ExternalLink
+                                        location='admin_console'
+                                        href={DocLinks.SETUP_PERFORMANCE_MONITORING}
+                                    >
+                                        {msg}
+                                    </ExternalLink>
+                                ),
+                            },
+                            isDisabled: it.any(
+                                it.not(it.userHasWritePermissionOnResource(RESOURCE_KEYS.ENVIRONMENT.PERFORMANCE_MONITORING)),
+                                it.configIsFalse('MetricsSettings', 'Enable'),
+                            ),
+                            isHidden: it.configIsFalse('FeatureFlags', 'ClientMetrics'),
+                        },
                         {
                             type: 'text',
                             key: 'MetricsSettings.ListenAddress',

webapp/channels/src/i18n/en.json

@@ -1472,6 +1472,8 @@
   "admin.manage_tokens.userAccessTokensNone": "No personal access tokens.",
   "admin.member_list_group.name": "Name",
   "admin.member_list_group.notFound": "No users found",
+  "admin.metrics.enableClientMetricsDescription": "When true, Mattermost will enable performance monitoring collection for web and desktop app users. Please see <link>documentation</link> to learn more about configuring performance monitoring for Mattermost.",
+  "admin.metrics.enableClientMetricsTitle": "Enable Client Performance Monitoring:",
   "admin.metrics.enableDescription": "When true, Mattermost will enable performance monitoring collection and profiling. Please see <link>documentation</link> to learn more about configuring performance monitoring for Mattermost.",
   "admin.metrics.enableTitle": "Enable Performance Monitoring:",
   "admin.metrics.listenAddressDesc": "The address the server will listen on to expose performance metrics.",