Actually apply the pre-commit fixers to the codebase.

This can be redone manually with
`pre-commit run --all`

While the pre-commit hook could be merged to run locally,
it is much cleaner to align all the files to best-practice
syntax in a single commit. It is also required for server-side
validation.

tools/fbsend/main.go

@@ -2,13 +2,14 @@ package main
 
 import (
 	"context"
-	firebase "firebase.google.com/go/v4"
-	"firebase.google.com/go/v4/messaging"
 	"flag"
 	"fmt"
-	"google.golang.org/api/option"
 	"os"
 	"strings"
+
+	firebase "firebase.google.com/go/v4"
+	"firebase.google.com/go/v4/messaging"
+	"google.golang.org/api/option"
 )
 
 func main() {