Try enabling PTS for non-CI builds (#5324)

Motivation:

We may be able to increase build speeds locally if we enable PTS for
non-CI builds

Modifications:

- Added a PTS setting for tests if the CI field is not set
-
https://docs.github.com/en/actions/learn-github-actions/variables#default-environment-variables

Result:

- Faster local builds

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build.gradle

@@ -50,6 +50,7 @@ gradle.buildFinished({ result ->
     }
 })
 
+def isCi = System.getenv("CI") != null
 allprojects {
     // Add common JVM options such as max memory and leak detection.
     tasks.withType(JavaForkOptions) {
@@ -124,6 +125,10 @@ allprojects {
                 failOnPassedAfterRetry = rootProject.findProperty('failOnPassedAfterRetry') != 'false'
             }
         }
+
+        predictiveSelection {
+            enabled.set(!isCi)
+        }
     }
 }