Change resource.resource_metadata to text type

The existing resource.resource_metadata column size is 5k chars,
which is not enough for some large JSON metadata payload,
so change to as Text column to make sure store all JSON string
without truncating.

Fixes bug #1220683

Change-Id: Ide8c6b94f1ae56d76fe3d5b6238d44e498e67c03
Merge "Change resource.resource_metadata to text type"