Don't reboot for memcg MaxActivationDepth reduction

19% of 25Q2 Beta unenrollment has been due to reboots. Let's avoid the
one for when experiment server flags change memcg device configuration.
We'll try to use the timestamps of flag rollout/rollback to look at
metrics (and hopefully it's not too noisy).

Bug: 393588812
Test: setprop persist.device_config.mglru_native.lru_gen_config all
Test: setprop persist.device_config.mglru_native.lru_gen_config none
Test: Observe no reboot
Ignore-AOSP-First: 25Q2 Beta Experiment only go/android-memcgv2-exp
Change-Id: I50d9be83756ce73d24636d992fcc528debeea1fd