[Android] Use library Context to get Inflater for shared mode

For color picker on Android, it uses ColorPickerAdvanced and
ColorPickerSimple which is customized view. So the inflater
should contain the ClassLoader which has loaded the relevant
classes. As for shared mode, it's library Context.

BUG=https://crosswalk-project.org/jira/browse/XWALK-1534
Merge pull request #1844 from wang16/color_picker_crash

[Android] Use library Context to get Inflater for shared mode