[Android] Check the local path file in packaging tool.

The webapp can be created successfully when the local path file
of launching application doesn't exist. This fix resolves this
issue by checking whether this file exists, when it doesn't exist,
related information is prompted and packaging is stopped.

BUG=XWALK-1212
Merge pull request #1732 from ShDavidliu/LocalPath

[Android] Check the local path file in packaging tool.