fix(gradle): move compdef line (#11488)

plugins/gradle/_gradle

@@ -1,3 +1,6 @@
+#compdef gradle gradlew gw
+# THE LINE ABOVE MUST BE THE FIRST LINE OF THIS FILE IN ORDER FOR COMPLETION TO WORK
+
 #
 # Taken from https://github.com/gradle/gradle-completion
 # Copyright (c) 2017 Eric Wendelin
@@ -21,8 +24,6 @@
 # SOFTWARE.
 # Terms
 
-#compdef gradle gradlew gw
-
 __gradle-set-project-root-dir() {
     local dir=`pwd`
     project_root_dir=`pwd`