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

(cherry picked from commit 96fea8bb94d2d26c2447a5e3415a7988186232af)
bug fix possible NPE while startProcessLocked()

In case, process doesn't create well while startingProcessLocked().
There is possibility to make NPE.
Setting app's crash handler needs to be assigned after null check routine.

Change-Id: I67fb6427f72d93f79fed36eb44c47d37eafdac31

(cherry picked from commit 09014bed2dd9cfa62ee37dd8f0ce28ee2cc6b72f)