Refactor showmap into libsmapinfo am: 51b4ca64e7 am: e16e92e986 am: 8f8fa7ff4b

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

Change-Id: I032f9a5336f03ffa34b29fb522ee75d37e6aeec5
Signed-off-by: Automerger Merge Worker <[email protected]>