BUILD.gn files: Improve import formatting

The "# gn-format disable" comments are no longer necessary. Delete these
comments and reformat with a Vim macro and gn format.

Change-Id: Ia62c40ad73eef91187d0d443d6e3b0fa723e5aa9
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/21380
Reviewed-by: Armando Montanez <amontanez@google.com>
Commit-Queue: Wyatt Hepler <hepler@google.com>
diff --git a/pw_build/defaults.gni b/pw_build/defaults.gni
index 5c2077e..6d341e7 100644
--- a/pw_build/defaults.gni
+++ b/pw_build/defaults.gni
@@ -12,8 +12,8 @@
 # License for the specific language governing permissions and limitations under
 # the License.
 
-# gn-format disable
 import("//build_overrides/pigweed.gni")
+
 declare_args() {
   # Default configs and dependencies targets provided by the toolchain. These
   # are applied to all of the pw_* target types. They are set from a toolchain's