[Tizen] Temporarily disable Vulkan backend for Linux

impeller/tools/impeller.gni

@@ -22,15 +22,15 @@ declare_args() {
       (is_linux || is_win || is_android) && target_os != "fuchsia"
 
   # Whether the Vulkan backend is enabled.
-  impeller_enable_vulkan = (is_linux || is_win || is_android ||
-                            enable_unittests) && target_os != "fuchsia"
+  impeller_enable_vulkan =
+      (is_win || is_android || enable_unittests) && target_os != "fuchsia"
 
   # Whether playgrounds should run with Vulkan.
   #
   # impeller_enable_vulkan may be true in build environments that run tests but
   # do not have a Vulkan ICD present.
   impeller_enable_vulkan_playgrounds =
-      (is_linux || is_win || is_android) && target_os != "fuchsia"
+      (is_win || is_android) && target_os != "fuchsia"
 
   # Whether to use a prebuilt impellerc.
   # If this is the empty string, impellerc will be built.

tools/gn

@@ -546,7 +546,7 @@ def to_gn_args(args):
   # Enable Vulkan on all platforms except for iOS. This is just
   # to save on mobile binary size, as there's no reason the Vulkan embedder
   # features can't work on these platforms.
-  if gn_args['target_os'] not in ['ios', 'mac']:
+  if gn_args['target_os'] not in ['ios', 'mac', 'linux']:
     gn_args['skia_use_vulkan'] = True
     gn_args['skia_use_vma'] = False
     gn_args['shell_enable_vulkan'] = True