See go/pixel-perf-amm-experiment for more info.
(This change is a reland of ag/30770395 after fixing issues that caused a revert.)
Bug: 365855872
Test: build/flash; set .Perf__amm_experiment=true, observe auto_migration_margins_enable value changing 1->0; set .Perf__amm_experiment="", observe the value changing 0->1
Flag: NONE controlled by Mendel instead
Change-Id: I833ea7cd104b95abf80f2286e91f96a102d8086a
Signed-off-by: Dmitry Skiba <dskiba@google.com>
c0ac52ad63