Removed Commons dependency (#369)

* Removed Commons dependency

Signed-off-by: Arnau Mora Gras <arnyminerz@proton.me>

* Upgrade ical4android and get rid of unused commons versions

Signed-off-by: Arnau Mora <arnyminerz@proton.me>

* Replaced usage

Signed-off-by: Arnau Mora <arnyminerz@proton.me>

* Using bufferred readers

Signed-off-by: Arnau Mora <arnyminerz@proton.me>

---------

Signed-off-by: Arnau Mora Gras <arnyminerz@proton.me>
Signed-off-by: Arnau Mora <arnyminerz@proton.me>
Co-authored-by: Sunik Kupfer <kupfer@bitfire.at>