Trim maps after releasing the startup linear alloc. am: 8ce90803c9

Original change: https://android-review.googlesource.com/c/platform/art/+/2426115

Change-Id: Ie8c6273b57c6d893d42d84297042c69995a3f418
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>