Control fault injection with config files instead of build flags

Bug: 27724259
Change-Id: I65bdefed10b3fb85fcb9e1147eaf0687d7d438f4
diff --git a/otafault/ota_io.h b/otafault/ota_io.h
index 641a5ae..84187a7 100644
--- a/otafault/ota_io.h
+++ b/otafault/ota_io.h
@@ -26,6 +26,10 @@
 #include <stdio.h>
 #include <sys/stat.h>
 
+#define OTAIO_CACHE_FNAME "/cache/saved.file"
+
+void ota_set_fault_files();
+
 int ota_open(const char* path, int oflags);
 
 int ota_open(const char* path, int oflags, mode_t mode);