[Android] Add space support in name field of manifest.

This patch is add space support in name field of manifest.
If the app name contains blank space, replace it with underscore.

BUG=XWALK-1718
[Android] Add test case for canGoForward().

Before load any url, canGoForward should be false.
After load two urls, canGoForward should be false.
Navigate to back url, canGoForward should be true.
Merge pull request #1959 from wuhengzhi/character_handling

[Android] Add space support in name field of manifest.
Merge pull request #2003 from jinbang/test_api_canGoForward

[Android] Add test case for canGoForward().