[sample] Update sreen orientation sample to reflect Chromium 38 implementation

However, the sample fails on my ZTE with canary 9.38.199.0
The layout shall be restored as before.

BUG=https://crosswalk-project.org/jira/browse/XWALK-2372
[sample] Improve test description and remove 2 tests

 Impacted test case: New 0, Update 25, Delete 2
 Unit test platform: Android, Window Chrome
 Unit test result: all tests run well
Merge pull request #853 from zqzhang/XWALK-2372

[sample] Update sreen orientation sample to reflect Chromium 38 implemen...
[sample] Fix typo issue
Merge pull request #854 from Honry/Honry/sample-feedback

[sample] Improve test description and remove 2 tests