Doc: Adding a page which lists Android-friendly examples.

-list taken from manifestmeta.android.names variable from
 qtbase/doc/global
-doesn't include all of the examples tagged for Android; focus is on
 QML examples

Change-Id: I4f58af21840f7df903d16ca530f8fa7f4c7aaa37
Reviewed-by: Topi Reiniö <topi.reinio@digia.com>