fastboot: Refactor string constants to constants.h

This allows them to be shared between host and device
implementations.

Test: fastboot works
Bug: 78793464
Change-Id: I79271687850ade2a904fd03d6a97dad1a9ab8e1c
diff --git a/fastboot/fastboot.h b/fastboot/fastboot.h
index 50c70f3..a93c0ac 100644
--- a/fastboot/fastboot.h
+++ b/fastboot/fastboot.h
@@ -35,6 +35,8 @@
 
 #include <bootimg.h>
 
+#include "constants.h"
+
 class Transport;
 struct sparse_file;
 
@@ -47,9 +49,6 @@
 int64_t fb_upload_data(Transport* transport, const char* outfile);
 const std::string fb_get_error();
 
-#define FB_COMMAND_SZ 64
-#define FB_RESPONSE_SZ 64
-
 /* engine.c - high level command queue engine */
 bool fb_getvar(Transport* transport, const std::string& key, std::string* value);
 void fb_queue_flash(const std::string& partition, void* data, uint32_t sz);