Merge "Add a doc about `dex_preopt_check`." am: a3dc7921 am: eabde79e am: 7e9e1ae7

Original change: https://android-review.googlesource.com/c/platform/build/+/2098894



Change-Id: I3b4c4dded02a6c02dcbf8cf895f312123cdfcdf1
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>