feat: Update supported locations

PiperOrigin-RevId: 715968384

Author: sasha-gitg

google/cloud/aiplatform/constants/base.py

@@ -43,6 +43,7 @@
         "europe-west8",
         "europe-west9",
         "europe-west12",
+        "global",
         "me-central1",
         "me-central2",
         "me-west1",