build_packages: default to building Chrome from source

Due to backported Chrome commits to the R83 branch, we no longer have
compatible prebuilts.  Disable this flag here so developers can build
Chrome from source.  This doesn't impact release builders as they will
always build from source.

BUG=chromium:1080704
TEST=None

Change-Id: Ic0d1a2bac49a79d1c9fa1613395c1470cc6850d7
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosutils/+/2197238
Reviewed-by: Alex Klein <saklein@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
diff --git a/build_packages b/build_packages
index baf9e0c..7b8a89a 100755
--- a/build_packages
+++ b/build_packages
@@ -32,7 +32,7 @@
   "Calculate reverse dependencies on changed ebuilds."
 DEFINE_boolean autosetgov "${FLAGS_FALSE}" \
   "Automatically set cpu governor to 'performance'."
-DEFINE_boolean use_any_chrome "${FLAGS_TRUE}" \
+DEFINE_boolean use_any_chrome "${FLAGS_FALSE}" \
   "Use any Chrome prebuilt available, even if the prebuilt doesn't match exactly."
 
 # The --board_root flag specifies the environment variables ROOT and PKGDIR.