Set icu_disable_thin_archive on non-component chromeos builds

icu_disable_thin_archive is a GN arg which is set to true on
chrome-icu package of chromeos. See:
https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/refs/heads/master/chromeos-base/chrome-icu/chrome-icu-9999.ebuild#105

The other day I got an uprev failue due to a bug in a GN file.
See https://crbug.com/1129473 for the details. Perhaps it is
worthwhile to set a default value of this argument, so that
this type of error can be found much earlier, in a CQ step of
chromium.

Bug: chromium:1132766
Test: gn args pass with both is_component_build=true/false on chromeos
Change-Id: I27bcfa60da556e91afe2600a6cd3aadfddfedfe4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/deps/icu/+/2436994
Reviewed-by: Honglin Yu <[email protected]>
Reviewed-by: Ben Pastene <[email protected]>
Reviewed-by: Frank Tang <[email protected]>

Author: jmuk

config.gni

@@ -9,7 +9,7 @@ declare_args() {
 
   # If true, compile icu into a standalone static library. Currently this is
   # only useful on Chrome OS.
-  icu_disable_thin_archive = false
+  icu_disable_thin_archive = is_chromeos && !is_component_build
 }
 
 # Set to true if icu is being built from the Fuchsia tree.