[Android] Fix the crash of GetUserMedia

Crash happens when releasing the audio resource of localusermedia in
openSL ES. On Android there are two ways to get the audio input:
openSL ES and java Recording API. We swtich to the Recording API as a
workaround of the bug. The limitation is Recording API only be avaiable
after version 15 of SDK.

BUG=XWALK-1833
Merge pull request #172 from xingnan/1833

[Android] Fix the crash of GetUserMedia