Cleanup build.gradle

snet/build.gradle

@@ -1,13 +1,13 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 27
-    buildToolsVersion "27.0.3"
+    compileSdkVersion rootProject.ext.compileSdkVersion
+    buildToolsVersion rootProject.ext.buildToolsVersion
 
     defaultConfig {
         applicationId "com.topjohnwu.snet"
         minSdkVersion 21
-        targetSdkVersion 27
+        targetSdkVersion rootProject.ext.compileSdkVersion
         versionCode 1
         versionName "1.0"
     }
@@ -20,10 +20,6 @@ android {
     }
 }
 
-repositories {
-    google()
-}
-
 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     implementation 'com.google.android.gms:play-services-safetynet:7.0.0'  /* The oldest version */