Add OIDC Auth provider config class (#397)

Adds OIDC provider config class and base class. This is part of adding multi-tenancy support (see issue #332).

Author: micahstairs

src/main/java/com/google/firebase/auth/AuthProviderConfig.java

@@ -102,9 +102,9 @@ public T setDisplayName(String displayName) {
      *
      * @param enabled a boolean indicating whether the user can sign in with the provider
      */
-    public T setEnabled(boolean enabled) {
+    public CreateRequest setEnabled(boolean enabled) {
       properties.put("enabled", enabled);
-      return getThis();
+      return this;
     }
 
     Map<String, Object> getProperties() {

src/main/java/com/google/firebase/auth/OidcProviderConfig.java

@@ -21,6 +21,8 @@
 import com.google.api.client.util.Key;
 import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableMap;
+import java.net.MalformedURLException;
+import java.net.URL;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -80,6 +82,11 @@ public CreateRequest setClientId(String clientId) {
      */
     public CreateRequest setIssuer(String issuer) {
       checkArgument(!Strings.isNullOrEmpty(issuer), "issuer must not be null or empty");
+      try {
+        new URL(issuer);
+      } catch (MalformedURLException e) {
+        throw new IllegalArgumentException(issuer + " is a malformed URL", e);
+      }
       properties.put("issuer", issuer);
       return this;
     }

src/test/java/com/google/firebase/auth/OidcProviderConfigTest.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2020 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.firebase.auth;
+
+import org.junit.Test;
+
+public class OidcProviderConfigTest {
+  @Test(expected = IllegalArgumentException.class)
+  public void testInvalidIssuerUrl() {
+    new OidcProviderConfig.CreateRequest().setIssuer("not a valid url");
+  }
+}