Fix a small bug in setCustomUserClaims() auth snippet (#747)

* fix a small bug in setCustomUserClaims() auth snippet

* Revert changes in setCustomUserClaims and create new function setCustomUserClaimsTenant

Author: NhienLam

src/test/java/com/google/firebase/snippets/FirebaseAuthSnippets.java

@@ -1150,6 +1150,33 @@ public void customClaimsVerifyTenant(
     // [END verify_custom_claims_tenant]
   }
 
+  public static void setCustomUserClaimsTenant(TenantAwareFirebaseAuth tenantAuth,
+      String uid) throws FirebaseAuthException {
+    // [START set_custom_user_claims_tenant]
+    // Set admin privilege on the user corresponding to uid in a specific tenant.
+    Map<String, Object> claims = new HashMap<>();
+    claims.put("admin", true);
+    tenantAuth.setCustomUserClaims(uid, claims);
+    // The new custom claims will propagate to the user's ID token the
+    // next time a new one is issued.
+    // [END set_custom_user_claims_tenant]
+
+    String idToken = "id_token";
+    // [START verify_custom_claims_tenant]
+    // Verify the ID token first.
+    FirebaseToken decoded = tenantAuth.verifyIdToken(idToken);
+    if (Boolean.TRUE.equals(decoded.getClaims().get("admin"))) {
+      // Allow access to requested admin resource.
+    }
+    // [END verify_custom_claims_tenant]
+
+    // [START read_custom_user_claims_tenant]
+    // Lookup the user associated with the specified uid in a specific tenant.
+    UserRecord user = tenantAuth.getUser(uid);
+    System.out.println(user.getCustomClaims().get("admin"));
+    // [END read_custom_user_claims_tenant]
+  }
+
   public void generateEmailVerificationLinkTenant(
       TenantAwareFirebaseAuth tenantAuth,
       String email,