[Android] Use intent actions to handle navigation according to MIME type.

Currently only "application/*" MIME type are handled by intent actions,
for other MIME types (text/*, video/*...) are still handled by XWalk.

BUG=XWALK-1560
[Android] Add the test case for addJavascriptInterface.

In this test case, we should use "@JavascriptInterface", it's from
"org.xwalk.core.JavascriptInterface", not
"android.webkit.JavascriptInterface".
In addition, if the target sdk version will be equal to or greater
than 17, "@JvascriptInterface" is required.

BUG=XWALK-1595
Merge pull request #1868 from sqliu/handle-mime

[Android] Use intent actions to handle navigation according to MIME type...
Merge pull request #1875 from wuhengzhi/addJavascriptInterface

[Android] Add the test case for addJavascriptInterface.