Revert^2 "libcore: Extend sun.misc.Unsafe presence in the Core Platform API"

This relands d477f4e609422348bb6be32cd3464bbc9bb7dd0e and reverts
commit 155369a6c1bfdd02ec98dcd2d22112eeff658337. The revert was based
on a build that did not have both the art and libcore changes present.

Bug: 144502743
Test: boot device && adb logcat | grep "Core platform"

Change-Id: I4eff1d3e4237290660a4b028f1a0cd326e829adb
2 files changed