Floss: fix from_db to use attribute_handle

Sometimes, the attribute_handle might not be the same as the
instance_id for an attribute. Change from_db to use the
attribute_handle so it can be the reverse operation of into_db
correctly.

Bug: 267557929
Test: Manually
Tag: #floss
Change-Id: I61e6c6b9befc613c310a201c7baaebdf2b5386b1