import: make it work most of the time with git repos

This includes real tests too.

tests/source-files/cn.wildfirechat.chat/build.gradle

@@ -0,0 +1,41 @@
+// Top-level build file where you can add configuration options common to all sub-projects/modules.
+
+buildscript {
+
+    repositories {
+        google()
+        jcenter()
+        mavenCentral()
+    }
+    dependencies {
+        classpath 'com.android.tools.build:gradle:3.4.2'
+        classpath 'com.github.dcendents:android-maven-gradle-plugin:2.1'
+
+        // NOTE: Do not place your application dependencies here; they belong
+        // in the individual module build.gradle files
+    }
+}
+
+allprojects {
+    repositories {
+        google()
+        jcenter()
+        maven {
+            url "http://developer.huawei.com/repo/"
+        }
+
+        maven { url 'https://jitpack.io' }
+        maven { url 'https://dl.bintray.com/jenly/maven' }
+    }
+    configurations {
+        all {
+            resolutionStrategy {
+                //force "android.arch.lifecycle:runtime:1.1.1"
+            }
+        }
+    }
+}
+
+task clean(type: Delete) {
+    delete rootProject.buildDir
+}