Add StaticProperties and MetadataReader

MetadataReader provides a clean wrapper around getting
and translating certain metadata values in a nice form.

StaticProperties will be used by Camera as the source of
truth for metadata properties, extracted directly from a reader,
rather than calling down into the device again.

BUG: 31044638
TEST: unit tests pass
Change-Id: I712a80f87e629a7288c678637de0eae0225acf96
9 files changed