remove references to goma

goma is not maintained anymore.

Bug: 41489832
Change-Id: I3e287cd9ac547fe1df93dc21e39db8b8f1f56eff
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/third_party/libunwindstack/+/5599420
Reviewed-by: Mike Wittman <wittman@chromium.org>

README.chromium

diff --git a/README.chromium b/README.chromium
index a8a2fc1..ae3e621 100644
--- a/README.chromium
+++ b/README.chromium
@@ -74,7 +74,7 @@
     # Build `stack_unwinder` module in component debug build.
     gn gen ../../out/libunwindstack_test_build --args=" \
       target_os=\"android\" \
-      use_goma=true \
+      use_remoteexec=true \
       is_component_build=true \
       is_debug=true" && \
     autoninja -C ../../out/libunwindstack_test_build stack_unwinder