FFL-1294: Fix FFE_FLAGS Remote Config handler payload format (#6754)

The FFE_FLAGS RC handler was incorrectly expecting a wrapped payload with
conf.flag_configuration, but Remote Config delivers direct UFC payloads.

Changes:
- Fixed: this.openfeature._setConfiguration(conf.flag_configuration)
- To: this.openfeature._setConfiguration(conf)

Author: leoromanovsky

packages/dd-trace/src/proxy.js

@@ -164,7 +164,7 @@ class Tracer extends NoopProxy {
           rc.setProductHandler('FFE_FLAGS', (action, conf) => {
             // Feed UFC config directly to OpenFeature provider
             if (action === 'apply' || action === 'modify') {
-              this.openfeature._setConfiguration(conf.flag_configuration)
+              this.openfeature._setConfiguration(conf)
             }
           })
         }

packages/dd-trace/test/proxy.spec.js

@@ -372,7 +372,7 @@ describe('TracerProxy', () => {
         proxy.openfeature // Trigger lazy loading
 
         const flagConfig = { flags: { 'test-flag': {} } }
-        handlers.get('FFE_FLAGS')('apply', { flag_configuration: flagConfig })
+        handlers.get('FFE_FLAGS')('apply', flagConfig)
 
         expect(openfeatureProvider._setConfiguration).to.have.been.calledWith(flagConfig)
       })
@@ -384,7 +384,7 @@ describe('TracerProxy', () => {
         proxy.openfeature // Trigger lazy loading
 
         const flagConfig = { flags: { 'modified-flag': {} } }
-        handlers.get('FFE_FLAGS')('modify', { flag_configuration: flagConfig })
+        handlers.get('FFE_FLAGS')('modify', flagConfig)
 
         expect(openfeatureProvider._setConfiguration).to.have.been.calledWith(flagConfig)
       })