Update the main activity

[hckhanh]

I figure out, you can use ViewAnimator to run the Search animation instead of FrameLayout. It optimized the animation process. But I think it's pretty slow. Do you have any idea to optimize this. I have upgrade the Gradle version and Android Build tool version too.

Changes:

• Change FrameLayout in activity_main.xml to ViewAnimator
• Upgrade Gradle, Android Build tool version

[johnjeremih]

I did an upgrade to the source code check it out