Synthetics Update: Support for Java runtime handler pattern.

Author: AWS

.changes/next-release/feature-Synthetics-e0da551.json

@@ -0,0 +1,6 @@
+{
+    "type": "feature",
+    "category": "Synthetics",
+    "contributor": "",
+    "description": "Support for Java runtime handler pattern."
+}

services/synthetics/src/main/resources/codegen-resources/service-2.json

@@ -881,7 +881,7 @@
       "type":"string",
       "max":128,
       "min":1,
-      "pattern":"^([0-9a-zA-Z_-]+\\/)*[0-9A-Za-z_\\\\-]+\\.[A-Za-z_][A-Za-z0-9_]*$"
+      "pattern":"^([0-9a-zA-Z_-]+(\\/|\\.))*[0-9A-Za-z_\\\\-]+(\\.|::)[A-Za-z_][A-Za-z0-9_]*$"
     },
     "ConflictException":{
       "type":"structure",