storage: Don't list removed volumes in storage list

 * Don't tell apps that USB storage or empty SD slots are available for
   use. This fixes errors about trying to create dirs in vold as well
   as the relevant CTS cases.

Change-Id: Ic763d40c19b0bb9f7497cc1515baf1661d76e9ee
Separate Android Encryption Password from Lockscreen Password

This permits the use of a different (hopefully longer and more complex!) encryption
password, while using a simpler (and easier to type) lockscreen password.

Change-Id: Ia35fdcc769eee8fd7891678a532dafa0f4b3ba04
frameworks: Smooth background gradient

Credit to UBER for the images

Change-Id: I3655e9917610348100fa6cb5cede66a63ca82538
DocumentsUI: Fix the issue of download status was displayed incompletely

The layout arrangement of date, size and summary are unreasonable.
Text was ellipsized when summary has too much characters.

Reconfigure "layout_weight" of date, size and summary can fix this
issue.

CRs-Fixed: 619201

Change-Id: I0c00d08d4793a38b80988378b4b510bdb3bf8720