Replace vector usage in collect_vma with map am: 92fcf5f1ca am: 9b86412776 am: c33bf38aba am: dfd81aa62a

Original change: https://android-review.googlesource.com/c/platform/system/memory/libmeminfo/+/2196974

Change-Id: I2b3a839867f6b806e0912d140fb200eb85c72f5b
Signed-off-by: Automerger Merge Worker <[email protected]>