PropTypes parsing no more works because RN now supports percents

[andrey-skl]

I have markup like this:

<div style="padding-left: 6px">
test
</div>

This fails to get parsed into styles {paddingLeft: 6} and parses into {paddingLeft: '6px'} instead, because View's PropTypes now accept "string" for such properties, because they support "100%"-like styles now.

So this check not working anymore.
It still renders somehow on iOS, but on Android it causes such error:
Error while updating property 'paddingLeft' in shadow node of type: RCTView updateShadowNodeProp ViewManagersPropertyCache.java:111 setProperty ViewManagerPropertyUpdater.java:148 updateProps ViewManagerPropertyUpdater.java:52 updateProperties ReactShadowNode.java:264 createView UIImplementation.java:184 createView UIManagerModule.java:245 invoke Method.java:-2 invoke BaseJavaModule.java:345 invoke JavaModuleWrapper.java:136 run NativeRunnable.java:-2 handleCallback Handler.java:751 dispatchMessage Handler.java:95 dispatchMessage MessageQueueThreadHandler.java:31 loop Looper.java:154 run MessageQueueThreadImpl.java:196 run Thread.java:761