More memory for pbi indexing

Author: kvg

wdl/tasks/Utility/PBUtils.wdl

@@ -1038,7 +1038,7 @@ task PBIndex {
     #########################
     RuntimeAttr default_attr = object {
         cpu_cores:          1,
-        mem_gb:             4,
+        mem_gb:             16,
         disk_gb:            disk_size,
         boot_disk_gb:       10,
         preemptible_tries:  0,