Remove process restrictions on dmabuf_dump for statsd

We used to only pull data for managed processes, but it's imperative we
get stats for other heavy users of dmabufs (e.g. surfaceflinger).

Test: manual, atest ProcessDmabufMemoryTests
Bug: 183708249
Change-Id: I27695112a2b787884ec3f07bab66d298a166c869