Fix flags in chromium* args.gn files (#4420)

b/377271824

While renaming the chromium and cobalt builders:
#4399 args.gn files was not set
correctly.
This PR sets the appropriate args.gn for chromium and cobalt builds for
all platforms.

cobalt/build/configs/chromium_android-arm/args.gn

@@ -1,4 +1,3 @@
 target_os = "android"
 target_cpu = "arm"
 is_cobalt = false
-treat_warnings_as_errors = false

cobalt/build/configs/chromium_android-arm64/args.gn

@@ -1,4 +1,3 @@
 target_os = "android"
 target_cpu = "arm64"
 is_cobalt = false
-treat_warnings_as_errors = false

cobalt/build/configs/chromium_android-x86/args.gn

@@ -1,4 +1,3 @@
 target_os = "android"
 target_cpu = "x86"
 is_cobalt = false
-treat_warnings_as_errors = false

cobalt/build/configs/chromium_linux-x64x11/args.gn

@@ -4,8 +4,3 @@ is_cobalt = false
 
 # TODO(b/376141256): Decide if this flag is needed here or in .gclient file
 chrome_pgo_phase = 0
-
-# Vulkan is a new rendering (and presentation, and more) API intended to replace
-# E/GL(ES). Partners are only required to support upto GLES 2.0 : https://developers.google.com/youtube/cobalt/docs/reference/starboard/modules/16/gles#gles_version
-# Disable Vulkan until we formally decide to support it.
-enable_vulkan = false

cobalt/build/configs/linux-x64x11/args.gn

@@ -5,3 +5,8 @@ use_ozone = true
 
 # TODO(b/376141256): Decide if this flag is needed here or in .gclient file
 chrome_pgo_phase = 0
+
+# Vulkan is a new rendering (and presentation, and more) API intended to replace
+# E/GL(ES). Partners are only required to support upto GLES 2.0 : https://developers.google.com/youtube/cobalt/docs/reference/starboard/modules/16/gles#gles_version
+# Disable Vulkan until we formally decide to support it.
+enable_vulkan = false