Increase fastboot timeout to 30 seconds

Some OEM commands can take quite a while.
The current 10 second timeout is too small.

Test: fastboot tool
Change-Id: Icf59615919c92dc85807abe3ec5793504cf7a162
diff --git a/fastboot/fastboot_driver.h b/fastboot/fastboot_driver.h
index 9fdd317..8af1743 100644
--- a/fastboot/fastboot_driver.h
+++ b/fastboot/fastboot_driver.h
@@ -57,7 +57,7 @@
 
 class FastBootDriver {
   public:
-    static constexpr int RESP_TIMEOUT = 10;  // 10 seconds
+    static constexpr int RESP_TIMEOUT = 30;  // 30 seconds
     static constexpr uint32_t MAX_DOWNLOAD_SIZE = std::numeric_limits<uint32_t>::max();
     static constexpr size_t TRANSPORT_CHUNK_SIZE = 1024;