Use proxy for dependencies (#9263)

Author: randomanderson

gradle/forbiddenapis.gradle

@@ -1,9 +1,22 @@
 buildscript {
   repositories {
-    maven {
-      url "https://plugins.gradle.org/m2/"
+    mavenLocal()
+    if (project.rootProject.hasProperty("gradlePluginProxy")) {
+      maven {
+        url project.rootProject.property("gradlePluginProxy")
+        allowInsecureProtocol true
+      }
     }
+    if (project.rootProject.hasProperty("mavenRepositoryProxy")) {
+      maven {
+        url project.rootProject.property("mavenRepositoryProxy")
+        allowInsecureProtocol true
+      }
+    }
+    gradlePluginPortal()
+    mavenCentral()
   }
+
   dependencies {
     classpath "de.thetaphi:forbiddenapis:3.8"
   }