feat: keyboard avoid

[mgefimov]

keyboard avoidance support added #62

closes #62

[vonovak]

hello @mgefimov and thank you fro your PR!

as it is now, the position updates even when the toast is not occluded by keyboard:

for example, when you display toast like this:

Toast.showWithGravity(
                'This is a centered toast.',
                Toast.SHORT,
                Toast.CENTER,
              );

and then show the keyboard, the toast moves up, but I would expect it to stay in place. What do you think about implementing keyboard avoidance only if gravity is bottom?

[mgefimov]

Hello @vonovak, thank you for your review! I have implemented keyboard avoidance only if gravity is bottom.

[vonovak]

thank you, merry Christmas! 🎄 😄