[Android] Fix the build issue caused by different Android OS Version.

Since different Android APIs are imported in different Android OS version,
the OS version with lower API level uses the API in high API level, which
causes issue. This fix resolves the issue by adding the control condition
in the API uses of different API levels.

BUG=https://crosswalk-project.org/jira/browse/XWALK-1081
Merge pull request #1657 from ShDavidliu/APILevel

[Android] Fix the build issue caused by different Android OS Version.