Moving to newer SDK and build framework.

build.gradle

@@ -1,15 +1,17 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 buildscript {
     repositories {
-        jcenter()
+        google()
+        mavenCentral()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:0.13.2'
+        classpath "com.android.tools.build:gradle:7.0.2"
+
+        // NOTE: Do not place your application dependencies here; they belong
+        // in the individual module build.gradle files
     }
 }
 
-allprojects {
-    repositories {
-        jcenter()
-    }
-}
+task clean(type: Delete) {
+    delete rootProject.buildDir
+}