feat: Add support for new Vertex regions (#811)

Author: wanyixu199

google/cloud/aiplatform/constants.py

@@ -18,18 +18,22 @@
 DEFAULT_REGION = "us-central1"
 SUPPORTED_REGIONS = {
  "asia-east1",
+ "asia-east2",
  "asia-northeast1",
  "asia-northeast3",
+ "asia-south1",
  "asia-southeast1",
  "australia-southeast1",
  "europe-west1",
  "europe-west2",
+ "europe-west3",
  "europe-west4",
  "northamerica-northeast1",
  "us-central1",
  "us-east1",
  "us-east4",
  "us-west1",
+ "us-west2",
 }
 
 API_BASE_PATH = "aiplatform.googleapis.com"