allow mremap to use MEMRMREMAP_MAYMOVE flag

Bug: 151163101
Bug: 152908945
Test: see bug, shouldn't see crash in mediacodec minijail

Merged-In: If25dc5a56fe2f549d7867aa5a459b949be7e6947
Change-Id: I9835b0e8ef2e8286b5142c6bec9fb7796d3947cc
3 files changed