Merge "Rewrite the description about triggers" into main am: e649b78ed1

Original change: https://android-review.googlesource.com/c/platform/system/core/+/3502952

Change-Id: I935dcf5e424b68b9e12a29ac68f05afd0019f184
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>