Don't count the nonresident arena bytes in metadata_bytes when we are reporting resident bytes.
Don't count the nonresident arena bytes in metadata_bytes when we are reporting resident bytes.

Note: currently, the nonresident bytes on the arena are all from madvised-away old slabs due to the dynamic slab experiment.
PiperOrigin-RevId: 450034947
Change-Id: I63890fe3856875646bf69808352be6a2cb6ddd0d

google/tcmalloc,google/tcmalloc,google/tcmalloc