Merge "documenting optimized flash super" into main am: a3b232c30c

Original change: https://android-review.googlesource.com/c/platform/system/core/+/2725774

Change-Id: I68a8ae36335a2aec2ea1e085a672da649552d319
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>