extract_utils: Add flag to disable pinning

* We might want to disable pinning entirely for an extract run.
 * Set DISABLE_PINNING=1 to turn it off and override everything.

Change-Id: I1be90dda68f0de1c5f5a70c946052d70bfaab7ed

build/tools/extract_utils.sh

@@ -828,7 +828,7 @@ function extract() {
 
         # Check pinned files
         local HASH="${HASHLIST[$i-1]}"
-        if [ ! -z "$HASH" ] && [ "$HASH" != "x" ]; then
+        if [ "$DISABLE_PINNING" != "1" ] && [ ! -z "$HASH" ] && [ "$HASH" != "x" ]; then
             local KEEP=""
             local TMP="$TMP_DIR/$FROM"
             if [ -f "$TMP" ]; then