Adding flag to flash only static partitions

adding in --exclude-dynamic-partitions to flash only bootloader
partitions and skip the rest. Super optimization will be turned off as
well when this flag is enabled

Test: fastboot flashall --exclude-dynamic-partitions

Change-Id: I4b9d70b7f6179bf079991bf3a20aade64cfe9935
diff --git a/fastboot/fastboot.h b/fastboot/fastboot.h
index f6ffb64..3fb00e0 100644
--- a/fastboot/fastboot.h
+++ b/fastboot/fastboot.h
@@ -98,6 +98,7 @@
     bool force_flash = false;
     bool should_optimize_flash_super = true;
     bool should_use_fastboot_info = true;
+    bool exclude_dynamic_partitions = false;
     uint64_t sparse_limit = 0;
 
     std::string slot_override;