I'm a python developer with little experience creating android apps in java and want to create an app that will access my university web portal, retrieve some data and show on a view.
So, after researching Kivy, I have a few questions:
1) Which one is easier and faster to develop android apps?
2) Does Kivy have any android feature limitations?
3) And finally, would an android app developed using kivy run as fast as one developed using java?
To complete inclement's answer, pyjnius indeed allows to access a lot of the android api. But it's not perfect, calling existing classes is not always enough, and an android programmer often need to create code that will be called by android to manage events, there are two ways to do that, both used by the android api. 

The first one is interfaces: you need to create a class that implement an existing java interface, pyjnius can do that, you create a python class and declare which java interface it implements, and have a decorator to declare the methods you have to declare.
The second is subclassing, you need to subclass an existing java class and override some methods, and we don't have a way to do that with pyjnius yet, so for these ones, you'd have to create a java class and use it in your program (fortunately you can mix that with kivy/pyjnius, it's just can't be 100% python in that scenario).

So it can be worth a look to the api beforehand, to see if the parts of the android api you have to access requires that.
Difference between Kivy and Java for android apps