Update stable_properties.h

ro.boot.* are from kernel cmdline, and kernel is usually owned by SoC
vendor or ODM.
So those properties should be allowed as action triggers of
vendor/odm init scripts.

Additionally the state of mediadrm (/system/bin/mediadrmserver) should
be used to operate the state of drm HAL.
So init.svc.mediadrm should be whitelisted as an action trigger as well.

Bug: 36796459
Test: tested with walleye
Change-Id: Ic9f68162c577cc190f193063988ad04e42478e6e