Revert^3 "Add the mainline framework boot image extension to the default." am: 03a88039ce am: 42e72fa58f am: 88cdec4df3

Original change: https://android-review.googlesource.com/c/platform/art/+/2465993

Change-Id: Iea9f89e34b165ed94cf35bffd5211c4aa827a2f0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>