Revert "Set sdcard as non-removable (workaround for mediaprovider bug)"

As per http://review.androidarmv6.org/#/c/7165/

This reverts commit 8567ca32be989a9d9ebeb514875bbfe2df3b60b5.

Change-Id: I1903779160d02f11e24b6455111562ec650be86b