Add more parity with iOS (breaking change), refactor module, fix theming

[hansemannn]

Hey there,

this pull attempts to add more parity with iOS, especially for the returned profile inside the login event (commit 1). Also, this pull adds some meta files so this module can easily be developed inside Android Studio. Let me know if you want to take those changes as well or if I should remove them again.

Cheers!

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Also closes #30 and #9. I'd even argue that all open issues should be closed. Most of them (#28, #14, #29, #18, #17) are questions and should be moved to StackObverflow or TiSlack.

Download: ti.googlesignin-android-4.0.0.zip