Retain the original path to Kokkos and ArborX

cmake/CabanaConfig.cmakein

@@ -12,14 +12,24 @@
 include(CMakeFindDependencyMacro)
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}" )
 list(APPEND CMAKE_PREFIX_PATH @CMAKE_PREFIX_PATH@)
-find_dependency(Kokkos REQUIRED)
+find_package(Kokkos QUIET)
+if(NOT Kokkos_FOUND)
+  # If Kokkos was not found, try to use Kokkos used when building Cabana
+  set(Kokkos_DIR @Kokkos_DIR@)
+  find_dependency(Kokkos)
+endif()
 set(Cabana_ENABLE_MPI @Cabana_ENABLE_MPI@)
 if(Cabana_ENABLE_MPI)
   find_dependency(MPI REQUIRED CXX)
 endif()
 set(Cabana_ENABLE_ARBORX @Cabana_ENABLE_ARBORX@)
 if(Cabana_ENABLE_ARBORX)
-  find_dependency(ArborX REQUIRED)
+  find_package(ArborX QUIET)
+  if(NOT ArborX_FOUND)
+    # If ArborX was not found, try to use ArborX used when building Cabana
+    set(ArborX_DIR @ArborX_DIR@)
+    find_dependency(ArborX)
+  endif()
 endif()
 set(Cabana_ENABLE_GRID @Cabana_ENABLE_GRID@)
 set(Cabana_ENABLE_CAJITA @Cabana_ENABLE_CAJITA@) # FIXME: remove in next release