Explicitly install RemoteProvisioner for keymint

This is effectively a no-op change; both packages are installed.
However, removing required and moving it to PRODUCT_PACKAGES cuts the
dependency from vendor modules to system-ext modules. This is needed for
vendor-only build test.

Test: build and see both packages are installed
Change-Id: I6620020a1eccfab08594c9be3b298611bd237f1d