libcore: Extend sun.misc.Unsafe presence in the Core Platform API

Android Platform uses protobuf and protobuf uses sun.misc.Unsafe.

(cherry picked from commit d477f4e609422348bb6be32cd3464bbc9bb7dd0e)

Bug: 144502743
Test: boot device && adb logcat | grep "Core platform"
Change-Id: I082c66b07dffb2e3d772514db8cc290e2bc00f27
2 files changed