hg: jdk/sandbox: 8242155: Enhance automated macos signing tests

[chris.hegarty at oracle.com]

Changeset: 9d4956ec144e
Author:    herrick
Date:      2020-04-10 16:21 -0400
URL:       https://hg.openjdk.java.net/jdk/sandbox/rev/9d4956ec144e

8242155: Enhance automated macos signing tests
Reviewed-by: asemenyuk, almatvee

! test/jdk/tools/jpackage/helpers/jdk/jpackage/test/Executor.java
! test/jdk/tools/jpackage/macosx/base/SigningBase.java