GSoC '18: Introduction & Request for guidance

Hello!
My name is Aditya Sood. I'm in the third year of pursuing my Dual Degree
(B.Tech+M.Tech) in CSE.

I have been using Libre on my laptop ever since I got it. I love using it,
given that it is so efficient and effective at getting the work done. Being
a regular and grateful user, I plan on giving back to the open source
community to the best of my capacity.

I would love to contribute to the Android app of LibreOffice. I am just
over the 'beginner' threshold, but resolute in my intention to learn
whatever is required to be able to make a meaningful contribution.

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Guidance Required:
I have run into some issues while trying to prepare myself for the Easy
Hacks exercise:

1) I have registered twice on the developer mailing list, but didn't
receive the confirmation e-mail both the times.

2) The app doesn't run on my device: I downloaded it from the PlayStore.
But directly opening the app shows an activity which doesn't lead to any of
the sub-parts (like it does on the PC version). I have attached the
screenshot of the activity with the error Toast message.

3) In the last step of building the codebase for Android (on https://wiki.
documentfoundation.org/Development/BuildingForAndroid), it instructs to
"...Create a file called autogen.input with a single line in it...". Could
you please clarify what is the single line to be put in it? The wiki
doesn't specify that clearly.

Thanks a lot

Best Regards
Aditya