safe-area Fix IME paddings

This reverts commit acfaa0cda35792e10fd1a67e711af582d633261f and fixes #38.

Overall this PR has 2 separate parts:

Revert of acfaa0cda35792e10fd1a67e711af582d633261f. The Stackoverflow thread mentioned in the original code does provide what it says on the tin - a way to get the height of just the keyboard, but in the case of this plugin that isn't the desired value, the bottom inset needs to be both the keyboard height and the navbar height together, otherwise content will be partially underneath the keyboard.
A change of which View the IME padding is applied to. If applied to the decor view it pushes any existing navigation bar background above the keyboard (and over the app's content).

I've tested this on several devices and android versions (11, 14, 15, though of course all on targetSdk 34), but only one app. So if there's anyone for whom alpha.8 worked correctly, there's gotta be something else in how our respective apps are configured, but I really can't think of anything that could do that.