download artifacts sources (#36323)

build.gradle

@@ -16,6 +16,8 @@ allprojects {
     apply plugin: 'java-test-fixtures'
     apply plugin: 'com.github.spotbugs'
     apply plugin: 'org.jetbrains.kotlin.jvm'
+    apply plugin: 'idea'
+
 
     // By default gradle uses directory as the project name. That works very well in a single project environment but
     // projects clobber each other in an environments with subprojects when projects are in directories named identically.
@@ -96,6 +98,13 @@ allprojects {
         }
     }
 
+    idea {
+        module {
+            downloadJavadoc = true
+            downloadSources = true
+        }
+    }
+
     spotbugs {
         ignoreFailures = false
         effort = Effort.valueOf('MAX')