The Java integ test which is run against the dist is failing because
the local `cdk-cx-api` Maven artifact cannot be found. Error message:

```
[ERROR] Failed to execute goal on project cdk-init-test: Could not
resolve dependencies for project com.myorg:cdk-init-test:jar:0.1: Failed
to collect dependencies at software.amazon.awscdk:core:jar:1.20.0 ->
software.amazon.awscdk:cdk-cx-api:jar:[1.20.0]: No versions available
for software.amazon.awscdk:cdk-cx-api:jar:[1.20.0] within specified
range -> [Help 1]
```

It is not clear to me why just this artifact cannot be found while for
example `core` can be found correctly, or why this problem only shows up
on the `release` branch, but after some reading of the Maven source and
local experimentation I have concluded that the proper filename of the
Maven metadata file should be `maven-metadata-local.xml` (instead of
just `maven-metadata.xml`), so we rename the files before rsync'ing them
into the repository now.