Rename the script and function to clarify their purpose

Author: abelgardep

check_script.sh renamed to verify_licenses_script.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 
-check_directory() {
+check_license_in_file() {
     if ! head -n 20 $FILE | grep -q "Permission is hereby granted, free of charge, to any person obtaining a copy"
     then
         echo "$FILE does not contain a current copyright header"
@@ -9,7 +9,7 @@ check_directory() {
 
 for FILE in $(find owncloudComLibrary/src -name "*.java" -o -name "*.kt")
 do
-    check_directory
+    check_license_in_file
 done
 
 ./gradlew ktlintFormat