installer for new block OTA system

(Cherry-pick back from master.)

Bug: 16984795
Change-Id: Ifa3d8345c5e2a0be86fb28faa080ca82592a96b4
diff --git a/updater/install.c b/updater/install.c
index 1986180..cdcdb8f 100644
--- a/updater/install.c
+++ b/updater/install.c
@@ -54,7 +54,7 @@
 #endif
 
 // Take a sha-1 digest and return it as a newly-allocated hex string.
-static char* PrintSha1(const uint8_t* digest) {
+char* PrintSha1(const uint8_t* digest) {
     char* buffer = malloc(SHA_DIGEST_SIZE*2 + 1);
     int i;
     const char* alphabet = "0123456789abcdef";