Update endpoint

firebase-vertexai/src/main/kotlin/com/google/firebase/vertexai/common/APIController.kt

@@ -17,7 +17,11 @@
 package com.google.firebase.vertexai.common
 
 import android.util.Log
+import com.google.firebase.Firebase
+import com.google.firebase.options
 import com.google.firebase.vertexai.common.server.FinishReason
+import com.google.firebase.vertexai.common.server.GRpcError
+import com.google.firebase.vertexai.common.server.GRpcErrorDetails
 import com.google.firebase.vertexai.common.util.decodeToFlow
 import com.google.firebase.vertexai.common.util.fullModelName
 import com.google.firebase.vertexai.type.RequestOptions
@@ -239,12 +243,32 @@ private suspend fun validateResponse(response: HttpResponse) {
   if (message.contains("quota")) {
     throw QuotaExceededException(message)
   }
-  if (error.details?.any { "SERVICE_DISABLED" == it.reason } == true) {
-    throw ServiceDisabledException(message)
+  getServiceDisabledErrorDetailsOrNull(error)?.let {
+    val errorMessage =
+      if (it.metadata?.get("service") == "firebasevertexai.googleapis.com") {
+        """
+        The Vertex AI for Firebase SDK requires the Firebase Vertex AI API
+        `firebasevertexai.googleapis.com` to be enabled for your project. Enable it by visiting 
+        the Firebase Console at https://console.firebase.google.com/project/${Firebase.options.projectId}/genai/vertex then 
+        retry. If you enabled this API recently, wait a few minutes for the action to propagate
+        to our systems and retry.
+      """
+          .trimIndent()
+      } else {
+        error.message
+      }
+
+    throw ServiceDisabledException(errorMessage)
   }
   throw ServerException(message)
 }
 
+private fun getServiceDisabledErrorDetailsOrNull(error: GRpcError): GRpcErrorDetails? {
+  return error.details?.firstOrNull {
+    it.reason == "SERVICE_DISABLED" && it.domain == "googleapis.com"
+  }
+}
+
 private fun GenerateContentResponse.validate() = apply {
   if ((candidates?.isEmpty() != false) && promptFeedback == null) {
     throw SerializationException("Error deserializing response, found no valid fields")

firebase-vertexai/src/main/kotlin/com/google/firebase/vertexai/common/server/Types.kt

@@ -163,4 +163,9 @@ internal data class GRpcError(
   val details: List<GRpcErrorDetails>? = null
 )
 
-@Serializable internal data class GRpcErrorDetails(val reason: String? = null)
+@Serializable
+internal data class GRpcErrorDetails(
+  val reason: String? = null,
+  val domain: String? = null,
+  val metadata: Map<String, String>? = null
+)

firebase-vertexai/src/main/kotlin/com/google/firebase/vertexai/type/RequestOptions.kt

@@ -25,8 +25,8 @@ import kotlin.time.toDuration
 class RequestOptions
 internal constructor(
   internal val timeout: Duration,
-  internal val endpoint: String = "https://firebaseml.googleapis.com",
-  internal val apiVersion: String = "v2beta",
+  internal val endpoint: String = "https://firebasevertexai.googleapis.com",
+  internal val apiVersion: String = "v1beta",
 ) {
 
   /**

firebase-vertexai/src/test/java/com/google/firebase/vertexai/common/APIControllerTests.kt

@@ -108,7 +108,7 @@ internal class RequestFormatTests {
       }
     }
 
-    mockEngine.requestHistory.first().url.host shouldBe "firebaseml.googleapis.com"
+    mockEngine.requestHistory.first().url.host shouldBe "firebasevertexai.googleapis.com"
   }
 
   @Test