disable android proxy debug logging and redact auth header (#36498)

Part of QA finding, disables debug logging, since we have no good way of
toggling based on Fleet's total logging level, but also added the Auth
header redaction just for good measures.

server/mdm/android/service/androidmgmt/proxy_client.go

@@ -8,6 +8,7 @@ import (
 	"log/slog"
 	"net/http"
 	"os"
+	"slices"
 
 	"github.com/fleetdm/fleet/v4/pkg/fleethttp"
 	"github.com/fleetdm/fleet/v4/server/contexts/ctxerr"
@@ -41,7 +42,13 @@ func NewProxyClient(ctx context.Context, logger kitlog.Logger, licenseKey string
 	}
 
 	slogLogger := slog.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{
-		Level: slog.LevelDebug,
+		ReplaceAttr: func(groups []string, a slog.Attr) slog.Attr {
+			if slices.Contains(groups, "request") && slices.Contains(groups, "headers") && a.Key == "Authorization" {
+				// Redact request Authorization headers
+				a.Value = slog.StringValue("REDACTED")
+			}
+			return a
+		},
 	}))
 	// We use the same client that we use to directly connect to Google to minimize issues/maintenance.
 	// But we point it to our proxy endpoint instead of Google.