DocumentsUI: Fix 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: Ic2db20a303dd1db7e2d3375e4b733d704daf393b
androidfw: Use the last package to create idmap.

Overlaid packages contain one or two package groups, the first one is system
package(android), and the second one is application package. So it should use
the last package group to create idmap.

When inspecting the idmap, similar as above.

Change-Id: I97e0179bc5b5acdcacbe6ec5b5b7c22af51d1d0b