Fixed falling ExplainAdminCommandTest test on php 5.3, fixed missing metadata mock, fixed EOL difference.

| Q             | A
| ------------- | ---
| Bug fix?      | yes (just for test)
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | n/a
| License       | MIT
| Doc PR        | n/a