tdf#42949 Remove unnecessary localization headers from avmedia

Found by searching for the header names and the localization function:
git grep -e \<mediamisc.hxx\> -e \<strings.hrc\> avmedia | xargs grep -c AvmResId | grep :0$ | grep -v /pch

Change-Id: I7e136a8c1c676fe75e200175345cf1b118de5e41
Reviewed-on: https://gerrit.libreoffice.org/52351Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

avmedia/source/avmediadummy.cxx

@@ -35,7 +35,6 @@
 #include <ucbhelper/content.hxx>
 
 #include <comphelper/storagehelper.hxx>
-#include <mediamisc.hxx>
 
 using namespace ::com::sun::star;
 

avmedia/source/viewer/mediawindow_impl.cxx

@@ -23,7 +23,6 @@
 #include "mediawindow_impl.hxx"
 #include "mediaevent_impl.hxx"
 #include <mediamisc.hxx>
-#include <strings.hrc>
 #include <bitmaps.hlst>
 #include <helpids.h>