Validate asec names.

Make sure asec names only contain alphanumeric, underscores,
dots, or dashes. Don't allow double dots.

Bug: 12504045

(cherry picked from commit 669626096513cf741646cf18a9e8ba246d359596)

Change-Id: Ia9d04f373aa95878b2e81584c4167dc2d4aa0c78
am 0de7c611: Validate asec names.

* commit '0de7c61102611ccd5df1ca48cb733bf037512c6b':
  Validate asec names.
am f4770dcf: am 0de7c611: Validate asec names.

* commit 'f4770dcf6ffe2baba16cbb290aba16f735c51962':
  Validate asec names.
am fd2dcf90: am f4770dcf: am 0de7c611: Validate asec names.

* commit 'fd2dcf905abd3dc76738fd864e3979bd6e5ce183':
  Validate asec names.
am 3e03bf8a: am fd2dcf90: am f4770dcf: am 0de7c611: Validate asec names.

* commit '3e03bf8a7ab9dcee8897f275c75adfcdb20e0fdc':
  Validate asec names.
am 35ab6119: am 3e03bf8a: am fd2dcf90: am f4770dcf: am 0de7c611: Validate asec names.

* commit '35ab611925aea29fc4088b5c3de7c8c77d956b8b':
  Validate asec names.
am 7f6932df: am 35ab6119: am 3e03bf8a: am fd2dcf90: am f4770dcf: am 0de7c611: Validate asec names.

* commit '7f6932df89756f796c3a1f04f748db39a0564561':
  Validate asec names.
am 2f0a1d66: am 7f6932df: am 35ab6119: am 3e03bf8a: am fd2dcf90: am f4770dcf: am 0de7c611: Validate asec names.

* commit '2f0a1d66585fb44f59d913d3417422486ef10225':
  Validate asec names.
am 7cf05b15: am 2f0a1d66: am 7f6932df: am 35ab6119: am 3e03bf8a: am fd2dcf90: am f4770dcf: am 0de7c611: Validate asec names.

* commit '7cf05b15b76b91aa07182e86a730d7552b23130c':
  Validate asec names.
Merge tag 'android-4.4.3_r1' of https://android.googlesource.com/platform/system/vold into staging

Android 4.4.3 release 1