Increase the worker count even more on the bots

Don't generally change the heuristics (to not trash peoples work machines)

Change-Id: I3ded45f8bc0aa595ddb08ff036484ae827c78bc5
diff --git a/build.gradle b/build.gradle
index d7c59dd..ce0bc7f 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1763,7 +1763,11 @@
       maxParallelForks = processors.intdiv(userDefinedCoresPerFork.toInteger()) ?: 1
     } else {
       // On normal work machines this seems to give the best test execution time (without freezing)
-      maxParallelForks = (processors.intdiv(3) ?: 1) + 1
+      maxParallelForks = processors.intdiv(3) ?: 1
+      // On low cpu count machines (bots) we under subscribe, so increase the count.
+      if (processors == 8) {
+        maxParallelForks = 4
+      }
     }
     println("NOTE: Max parallel forks " + maxParallelForks)