[wrt] Update android auto scripts
[wrt]Update host prefix path

[Detailed commit message (if have)]
Impacted TCs num(designed): New 0, update 4, deleted 0
Unit test platform: [tizen]
UT result: pass: 4, Fail 0
Merge pull request #847 from linshen/shen/wrt/update-manifest

[wrt]Update host prefix path
Merge pull request #845 from kangxu/kangxu/wrt/pyauto/updateScript

[wrt] Update android auto scripts
[wrt] Remove wrt invaid cases and update usecase
Merge pull request #850 from kangxu/kangxu/wrt/wrtandroid/updateCases

[wrt] Remove wrt invaid cases and update usecase
[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
update README.md
Merge pull request #851 from jennycao/sample

[sample] update README.md
[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