Doc: Added information about the tagged desktop examples

This change informs developers about listing the examples that are
tested for Android so that they don't annoy themselves by trying to
run examples that don't work.

Task-number: QTBUG-30173
Change-Id: I0c422ebf265247c96e63c22fc4a76f28eb37a7d3
Reviewed-by: Topi Reiniö <topi.reinio@digia.com>
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
Doc: Added information about the ADB driver requirement on Windows

The default USB drivers on Windows does not allow USB debugging
so the developers must install the ADB driver to test and debug their
application on the Android device.

Task-number: QTBUG-30173
Change-Id: I16ba4935b4b8dfda86584b3e8d15fa10b18e9a57
Reviewed-by: Topi Reiniö <topi.reinio@digia.com>
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
Reviewed-by: Nico Vertriest <nico.vertriest@digia.com>