Check if 'aab' target exists when adding <target>_make_aab as dependency

The global 'aab' target has its own switch QT_NO_GLOBAL_AAB_TARGET
that prevents it from being created. We need to check if 'aab' target
exists before adding <target>_make_aab as a dependency.

Pick-to: 6.3 6.2
Change-Id: Iea569e3b6c7dfb6d0efa60dd2001fb9de161f725
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

src/corelib/Qt6AndroidMacros.cmake

@@ -327,9 +327,11 @@ function(qt6_android_add_apk_target target)
     endif()
 
     # Make global apk and aab targets depend on the current apk target.
+    if(TARGET aab)
+        add_dependencies(aab ${target}_make_aab)
+    endif()
     if(TARGET apk)
         add_dependencies(apk ${target}_make_apk)
-        add_dependencies(aab ${target}_make_aab)
         _qt_internal_create_global_apk_all_target_if_needed()
     endif()