[scudo] Ensure proper allocator alignment in TSD test am: 43839dc421 am: f5a73051da am: 56b5fc25f2 am: bae9cab953

Original change: https://android-review.googlesource.com/c/platform/external/scudo/+/1740873

Change-Id: If651dc1f44b751236c7bc6d3e82dc7831e7f8cfa