[SysApps][Android] Refine display attributes based on latest spec

SPEC=http://www.w3.org/2012/sysapps/device-capabilities/
BUG=XWALK-1309
Merge pull request #1773 from halton/display_refine

[SysApps][Android] Refine display attributes based on latest spec
[Android] Restore the function for '--icon'.

This patch is to restore the function for '--icon'.
If the developer specify the icon in the command line, this icon
will be used instead of the icons in manifest.json.

BUG=https://crosswalk-project.org/jira/browse/XWALK-1368