fix: use unique action name in Level 10 OR MODIFY java action example

The previous Level 10 example tried to CREATE JaTest.FormatDate which
was already created at line 184, causing "java action already exists"
in the integration test. Use JaTest.PadString as a self-contained demo
so Level 10 does not conflict with the existing FormatDate action.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: ako

mdl-examples/doctype-tests/07-java-action-examples.mdl

@@ -1809,26 +1809,26 @@ drop java action JaTest.ComputeHash;
 -- team-shared setup scripts, migrations).
 
 -- 10.1: Create a Java action initially
-create java action JaTest.FormatDate(
+create java action JaTest.PadString(
   Input: string not null
 ) returns string
 as $$
 return Input.trim();
 $$;
 
 -- 10.2: Re-run the same script with CREATE OR MODIFY to update the body
-create or modify java action JaTest.FormatDate(
+create or modify java action JaTest.PadString(
   Input: string not null,
-  Format: string not null
+  PadChar: string not null,
+  Width: integer not null
 ) returns string
 as $$
-import java.time.LocalDate;
-import java.time.format.DateTimeFormatter;
-LocalDate date = LocalDate.parse(Input);
-return date.format(DateTimeFormatter.ofPattern(Format));
+String s = Input.trim();
+while (s.length() < Width) s = PadChar + s;
+return s;
 $$;
 
-drop java action JaTest.FormatDate;
+drop java action JaTest.PadString;
 
 -- ============================================================================
 -- Java Action Feature Summary