Merge "Drop unused PerBootDbKeepAlive type" into main am: 98e175b6f8

Original change: https://android-review.googlesource.com/c/platform/system/security/+/3037727

Change-Id: I90b4857dc4712c3b36873671b1a90c8177947a78
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>