Fix telemetry feature flag tests to set mock session host

The tests were failing because they called get_telemetry_client("test")
but the mock session didn't have .host set, so the telemetry client was
registered under a different key (likely None or MagicMock). This caused
the factory to return NoopTelemetryClient instead of the expected client.

Fixed by setting mock_session_instance.host = "test" in all three tests.

Author: samikshya-db

tests/unit/test_telemetry.py

@@ -391,6 +391,7 @@ def test_telemetry_enabled_when_flag_is_true(self, mock_http_request, MockSessio
         self._mock_ff_response(mock_http_request, enabled=True)
         mock_session_instance = MockSession.return_value
         mock_session_instance.guid_hex = "test-session-ff-true"
+        mock_session_instance.host = "test"  # Set host for telemetry client lookup
         mock_session_instance.auth_provider = AccessTokenAuthProvider("token")
         mock_session_instance.is_open = (
             False  # Connection starts closed for test cleanup
@@ -421,6 +422,7 @@ def test_telemetry_disabled_when_flag_is_false(
         self._mock_ff_response(mock_http_request, enabled=False)
         mock_session_instance = MockSession.return_value
         mock_session_instance.guid_hex = "test-session-ff-false"
+        mock_session_instance.host = "test"  # Set host for telemetry client lookup
         mock_session_instance.auth_provider = AccessTokenAuthProvider("token")
         mock_session_instance.is_open = (
             False  # Connection starts closed for test cleanup
@@ -451,6 +453,7 @@ def test_telemetry_disabled_when_flag_request_fails(
         mock_http_request.side_effect = Exception("Network is down")
         mock_session_instance = MockSession.return_value
         mock_session_instance.guid_hex = "test-session-ff-fail"
+        mock_session_instance.host = "test"  # Set host for telemetry client lookup
         mock_session_instance.auth_provider = AccessTokenAuthProvider("token")
         mock_session_instance.is_open = (
             False  # Connection starts closed for test cleanup