Provide encoding to String#getBytes()

Fixes ErrorProne complaint.

Change-Id: I706b225f98187bf5f86999ed5342d0072e57e314

org.eclipse.jgit.pgm.test/tst/org/eclipse/jgit/pgm/ToolTestCase.java

diff --git a/org.eclipse.jgit.pgm.test/tst/org/eclipse/jgit/pgm/ToolTestCase.java b/org.eclipse.jgit.pgm.test/tst/org/eclipse/jgit/pgm/ToolTestCase.java
index 5f6b38c..55db1a1 100644
--- a/org.eclipse.jgit.pgm.test/tst/org/eclipse/jgit/pgm/ToolTestCase.java
+++ b/org.eclipse.jgit.pgm.test/tst/org/eclipse/jgit/pgm/ToolTestCase.java
@@ -9,6 +9,7 @@
  */
 package org.eclipse.jgit.pgm;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 
@@ -213,7 +214,7 @@ protected static InputStream createInputStream(String[] inputLines) {
 
 	protected static InputStream createInputStream(List<String> inputLines) {
 		String input = String.join(System.lineSeparator(), inputLines);
-		InputStream inputStream = new ByteArrayInputStream(input.getBytes());
+		InputStream inputStream = new ByteArrayInputStream(input.getBytes(UTF_8));
 		return inputStream;
 	}