Android Viewer: Set SfxWorkWindow::bIsFullScreen to true again

Commit fd603be25f
("tdf#129394: Create formula bar also in non-DESKTOP case", 2019-12-19)
made 'bIsFullScreen' be initialized with 'false' unconditionally,
but this breaks the Fennec-based Android Viewer which crashed
or showed error message "Error: Cannot open <path_to_file>:
loadComponentFromURL returned an empty reference." whenever trying
to load a document.

Since that app has its own UI elements, there's no need to create
formula input bar etc. for it, so this basically "reverts" the above
commit for the Android Viewer case only.

Change-Id: I96c0bdc1c298872db8143f6ec178d143a27fd56b
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/90020
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>

sfx2/source/appl/workwin.cxx

@@ -17,6 +17,7 @@
  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  */
 
+#include <config_features.h>
 #include <config_feature_desktop.h>
 #include <comphelper/lok.hxx>
 #include <comphelper/processfactory.hxx>
@@ -459,7 +460,11 @@ SfxWorkWindow::SfxWorkWindow( vcl::Window *pWin, SfxFrame *pFrm, SfxFrame* pMast
     bDockingAllowed(true),
     bInternalDockingAllowed(true),
     bAllChildrenVisible(true),
+#if !defined(ANDROID) || HAVE_FEATURE_ANDROID_LOK
     bIsFullScreen( false ),
+#else // Fennec-based Android Viewer
+    bIsFullScreen( true ),
+#endif
 #if HAVE_FEATURE_DESKTOP
     bShowStatusBar( true ),
 #else