[Java] Add back scans statement.

build.gradle

@@ -103,6 +103,11 @@ def projectPom = {
     }
 }
 
+buildScan {
+    termsOfServiceUrl = 'https://gradle.com/terms-of-service'
+    apply from: 'gradle/build-scans.gradle'
+}
+
 configurations {
     shadow
 }

gradle/build-scans.gradle

@@ -1,4 +1,29 @@
+def acceptFile = new File(gradle.gradleUserHomeDir, "build-scans/aeron/gradle-scans-license-agree.txt")
+def env = System.getenv()
+boolean isCI = env.CI || env.TRAVIS
+boolean hasAccepted = isCI || env.AERON_GRADLE_SCANS_ACCEPT=='yes' || acceptFile.exists() && acceptFile.text.trim() == 'yes'
+boolean hasRefused = env.AERON_GRADLE_SCANS_ACCEPT=='no' || acceptFile.exists() && acceptFile.text.trim() == 'no'
+
 buildScan {
-    termsOfServiceUrl = 'https://gradle.com/terms-of-service'
-    termsOfServiceAgree = 'yes'
+    if (hasAccepted) {
+        termsOfServiceAgree = 'yes'
+    } else if (!hasRefused) {
+        gradle.buildFinished {
+            println """
+This build uses Gradle Build Scans to gather statistics, share information about 
+failures, environmental issues, dependencies resolved during the build and more.
+Build scans will be published after each build, if you accept the terms of 
+service, and in particular the privacy policy.
+Please read 
+   
+    https://gradle.com/terms-of-service 
+    https://gradle.com/legal/privacy
+and then:
+  - set the `AERON_GRADLE_SCANS_ACCEPT` to `yes`/`no` if you agree with/refuse the TOS
+  - or create the ${acceptFile} file with `yes`/`no` in it if you agree with/refuse
+And we'll not bother you again. Note that build scans are only made public if 
+you share the URL at the end of the build.
+"""
+        }
+    }
 }