Bugfx/revert 2783 2883

[lucky-chen]

• revert [Android]support "wx" in animation and wxtext #2783
• revert [Android] Change default value to from Float.NAN to 0 #2883

[weex-bot]

	Warnings
⚠️	Potential BREAK CHANGE. Modify public in android/sdk/src/main/java/com/taobao/weex/utils/WXViewUtils.java without metion it in commit message. You'd better add '@notdanger' in your commit log.
⚠️	No Changelog changes! - Can you add a Changelog? To do so,append your changes to the changelog.md
⚠️	Current pr not bind the milestone
⚠️	If your PR is about fixing a bug excluding crash the code,you should add the demo link in the PR description. Demo link: http://dotwe.org/vue

	Messages
📖	danger test finished.

Generated by 🚫 dangerJS against 30de3f6

[YorkShen]

Revert documentation as well.

apache/incubator-weex-site#491