Doc: update qml module version to 5.5.

And remove import statements from snippets.

Change-Id: I109beabd445186f96f0750b6f23fb623c125181e
Task-number: QTBUG-47620
Reviewed-by: Venugopal Shivashankar <venugopal.shivashankar@digia.com>
Reviewed-by: Topi Reiniö <topi.reinio@digia.com>

src/imports/multimedia/qdeclarativecameracapture.cpp

@@ -57,9 +57,6 @@ QT_BEGIN_NAMESPACE
     and cannot be created directly.
 
     \qml
-    import QtQuick 2.0
-    import QtMultimedia 5.0
-
     Item {
         width: 640
         height: 360