Fix junit test runner script placement.

In https://codereview.chromium.org/1708383002 the default placement of
Java runner scripts was changed, but some cases where scripts should
stay in the helper directory were missed, causing the tests to fail to
run on the bots which still looked in helper/.

Verified that these two are the only misplaced scripts listed in the
build being extracted by the test bot.

BUG=
R=peter@chromium.org

Review URL: https://codereview.chromium.org/1720863002 .

Cr-Commit-Position: refs/heads/master@{#376715}

components/components_tests.gyp

@@ -1672,6 +1672,7 @@
               'policy/android/junit/',
               'web_restrictions/junit/'
             ],
+            'wrapper_script_name': 'helper/<(_target_name)',
           },
           'includes': [ '../build/host_jar.gypi' ],
         },

testing/android/junit/junit_test.gyp

@@ -34,6 +34,7 @@
         'src_paths': [
           'javatests/src',
         ],
+        'wrapper_script_name': 'helper/<(_target_name)',
       },
       'includes': [
         '../../../build/host_jar.gypi',