Samples Showcase script warning does not clear after enabling required settings until GameObject is reselected

Steps to reproduce:

1. Create a new HDRP project
2. Import Water Samples from the HDRP package samples
3. Open the Rain scene
4. In the Hierarchy, select the Samples Showcase GameObject
5. In the Inspector, enable the required settings such as Screen Space Reflections
6. Observe the warning message in the Samples Showcase (Script) component

Actual results: The warning message persists even after enabling the required settings (e.g., Screen Space Reflections) until the GameObject is unselected and reselected

Expected results: The warning message should automatically disappear once the required settings are enabled without needing to reselect the GameObject

Reproducible with versions: 6000.0.48f1, 6000.1.0f1, 6000.2.0a9

Tested on (OS): Ubuntu 24

Notes:

•  This affects usability and may confuse users into thinking the setup is still incorrect. The script should update the UI immediately when the requirement conditions are met