Refactor showmap into libsmapinfo am: 51b4ca64e7 am: e16e92e986

Original change: https://android-review.googlesource.com/c/platform/system/memory/libmeminfo/+/2197935

Change-Id: I7cf76b202bdb6b0d0be4d75afd7d9b194efd5aa1
Signed-off-by: Automerger Merge Worker <[email protected]>