am 2c3c5c15: Merge "mount sdcard only on demand; fix sideload installs" into gingerbread

Merge commit '2c3c5c15d15faf1c9fa074851c57d0afa2a40d28' into gingerbread-plus-aosp

* commit '2c3c5c15d15faf1c9fa074851c57d0afa2a40d28':
  mount sdcard only on demand; fix sideload installs