Adding e4crypt support

Redirect all crypto calls to e4crypt equivalents if file level encryption
detected. Note this change implements only the ones needed for minimal
functionality.

Requires matching change:
  https://googleplex-android-review.git.corp.google.com/#/c/642778/

Change-Id: I622d1a91704de4b3ab655486e6d38cd6718e6016
3 files changed