[MM-63513] Turn Cross team search feature flag into a setting option (#30518)

* feat: Add EnableCrossTeamSearch configuration option to ServiceSettings

* feat: Add EnableCrossTeamSearch configuration option to ServiceSettings

* feat: Enable cross-team search by default

* include old FF in client config

e2e-tests/cypress/tests/support/api/on_prem_default_config.json

@@ -64,6 +64,7 @@
         "EnableEmojiPicker": true,
         "PostEditTimeLimit": -1,
         "TimeBetweenUserTypingUpdatesMilliseconds": 5000,
+        "EnableCrossTeamSearch": true,
         "EnablePostSearch": true,
         "EnableFileSearch": true,
         "MinimumHashtagLength": 3,

e2e-tests/playwright/support/server/default_config.ts

@@ -151,6 +151,7 @@ const defaultServerConfig: AdminConfig = {
         EnableEmojiPicker: true,
         PostEditTimeLimit: -1,
         TimeBetweenUserTypingUpdatesMilliseconds: 5000,
+        EnableCrossTeamSearch: true,
         EnablePostSearch: true,
         EnableFileSearch: true,
         MinimumHashtagLength: 3,
@@ -749,7 +750,6 @@ const defaultServerConfig: AdminConfig = {
         WebSocketEventScope: true,
         NotificationMonitoring: true,
         ExperimentalAuditSettingsSystemConsoleUI: false,
-        ExperimentalCrossTeamSearch: false,
         CustomProfileAttributes: false,
     },
     ImportSettings: {

e2e-tests/playwright/tests/functional/channels/search/team_selector.spec.ts

@@ -5,8 +5,6 @@ import {createRandomTeam} from '@e2e-support/server';
 import {expect, test} from '@e2e-support/test_fixture';
 
 test('team selector must show all my teams', async ({pw}) => {
-    pw.skipIfFeatureFlagNotSet('ExperimentalCrossTeamSearch', true);
-
     const {adminClient, user, team} = await pw.initSetup();
 
     // # create 2 more teams and add the user to them