Merge "init: Add a boot monitor for the second stage init" into main am: 2d69dd6055

Original change: https://googleplex-android-review.googlesource.com/c/platform/system/core/+/30846148

Change-Id: I8eea0d762d7d48f85033bf3423e343a12611b43d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>