Many of the Android samples rely on an options menu to work properly
but, at least on newer devices, the menu is permanently hidden by the
Android theme "Theme.NoTitleBar.Fullscreen", which means that most
of the examples were dysfunctional.

- drop hello-android sample

All samples use application style in android manifest instead of system calls in onCreate event now.

(cherry picked from commit bd12f636)
Signed-off-by: NAndrey Kamaev <andrey.kamaev@itseez.com>

(cherry picked from commit 47b96407)
Signed-off-by: NAndrey Kamaev <andrey.kamaev@itseez.com>

Android samples fixed - line endings are converted to unix style; autogenerated folders are added to ignore list