Retry tests only on CI server (#5349)

Retrying all tests by default is not great when developing tests. This
behavior could be missed by a developer and result in new flakiness
being introduced. This change will only enable retries when the "CI"
environment variable is present.

Signed-off-by: Andrew Ross <andrross@amazon.com>

Signed-off-by: Andrew Ross <andrross@amazon.com>

build.gradle

@@ -450,13 +450,16 @@ gradle.projectsEvaluated {
 }
 
 // test retry configuration
+boolean isCiServer = System.getenv().containsKey("CI")
 subprojects {
   apply plugin: "org.gradle.test-retry"
   tasks.withType(Test).configureEach {
     retry {
+      if (isCiServer) {
+        maxRetries = 3
+        maxFailures = 10
+      }
       failOnPassedAfterRetry = false
-      maxRetries = 3
-      maxFailures = 10
     }
   }
 }