Increase workers from 2 to 4

https://docs.github.com/en/actions/using-github-hosted-runners/using-github-hosted-runners/about-github-hosted-runners#standard-github-hosted-runners-for-public-repositories

Change-Id: I47723722e483333ad644ac1a6a28d71c11933236

.github/ci-gradle.properties

@@ -16,7 +16,7 @@
 
 org.gradle.daemon=true
 org.gradle.parallel=true
-org.gradle.workers.max=2
+org.gradle.workers.max=4
 org.gradle.configuration-cache=true
 org.gradle.configuration-cache.parallel=true