Update for libunwindstack shared_ptr MapInfos. Bug: 120606663 Test: Unit tests pass. Change-Id: Ieae157388e8571345ed8968a2b5c2aa34464689f Merged-In: Ieae157388e8571345ed8968a2b5c2aa34464689f (cherry picked from commit 853733b627dc5bbb07b2463a1f10f10ddee06bbc)