fix detach

cloud-anchors/app/src/main/java/it/norangeb/cloudanchors/MainActivity.kt

@@ -144,6 +144,7 @@ class MainActivity : AppCompatActivity() {
     }
 
     fun onClearClick(view: View) {
+        cloudAnchor?.detach()
         cloudAnchor = null
         cloudAnchorState = CloudAnchorState.LOCAL
     }

cloud-anchors/build.gradle

@@ -7,7 +7,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.2.1'
+        classpath 'com.android.tools.build:gradle:3.3.0'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
         classpath 'com.google.ar.sceneform:plugin:1.6.0'
         classpath 'com.google.gms:google-services:4.2.0' // google-services plugin

cloud-anchors/gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,6 @@
+#Wed Jan 16 21:40:50 CET 2019
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.6-all.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.10.1-all.zip