Added doc reference for Invalid WF and WL audience.

Author: vverman

oauth2_http/java/com/google/auth/oauth2/ExternalAccountAuthorizedUserCredentials.java

@@ -230,7 +230,8 @@ public String getTrustBoundaryUrl() throws IOException {
     Matcher matcher = WORKFORCE_AUDIENCE_PATTERN.matcher(getAudience());
     if (!matcher.matches()) {
       throw new IllegalStateException(
-          "The provided audience is not in the correct format for a workforce pool.");
+          "The provided audience is not in the correct format for a workforce pool. "
+              + "Refer: https://docs.cloud.google.com/iam/docs/principal-identifiers");
     }
     String poolId = matcher.group("pool");
     return String.format(

oauth2_http/java/com/google/auth/oauth2/ExternalAccountCredentials.java

@@ -648,7 +648,8 @@ public String getTrustBoundaryUrl() {
     }
 
     throw new IllegalStateException(
-        "The provided audience is not in a valid format for either a workload identity pool or a workforce pool.");
+        "The provided audience is not in a valid format for either a workload identity pool or a workforce pool."
+            + " Refer: https://docs.cloud.google.com/iam/docs/principal-identifiers");
   }
 
   @Nullable

oauth2_http/java/com/google/auth/oauth2/GoogleCredentials.java

@@ -339,10 +339,6 @@ TrustBoundary getTrustBoundary() {
     return trustBoundary;
   }
 
-  protected void setTrustBoundary(TrustBoundary trustBoundary) {
-    this.trustBoundary = trustBoundary;
-  }
-
   /**
    * Refreshes the trust boundary by making a call to the trust boundary URL.
    *

oauth2_http/javatests/com/google/auth/oauth2/AwsCredentialsTest.java

@@ -1422,7 +1422,7 @@ public void testRefresh_trustBoundarySuccess() throws IOException {
             .setSubjectTokenType("subjectTokenType")
             .build();
 
-    awsCredential.refreshAccessToken();
+    awsCredential.refresh();
 
     TrustBoundary trustBoundary = awsCredential.getTrustBoundary();
     assertNotNull(trustBoundary);

oauth2_http/javatests/com/google/auth/oauth2/ExternalAccountAuthorizedUserCredentialsTest.java

@@ -1269,7 +1269,8 @@ public void testRefresh_trustBoundaryFails_incorrectAudience() {
               credentials.refresh();
             });
     assertEquals(
-        "The provided audience is not in the correct format for a workforce pool.",
+        "The provided audience is not in the correct format for a workforce pool. "
+            + "Refer: https://docs.cloud.google.com/iam/docs/principal-identifiers",
         exception.getMessage());
   }
 

oauth2_http/javatests/com/google/auth/oauth2/ExternalAccountCredentialsTest.java

@@ -1305,7 +1305,8 @@ public void getTrustBoundaryUrl_invalidAudience_throws() {
             });
 
     assertEquals(
-        "The provided audience is not in a valid format for either a workload identity pool or a workforce pool.",
+        "The provided audience is not in a valid format for either a workload identity pool or a workforce pool. "
+            + "Refer: https://docs.cloud.google.com/iam/docs/principal-identifiers",
         exception.getMessage());
   }