Handle passing of extra file list to buildstrap

Previously we use base64, but it doesn't really work. For now just do a
silly temp file write and delete.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
diff --git a/androdeb b/androdeb
index d5c3552..d2190d9 100755
--- a/androdeb
+++ b/androdeb
@@ -198,9 +198,12 @@
 
 SKIP_COMPRESS=0; if [ ! -z "$BUILD_IMAGE" ]; then SKIP_COMPRESS=1; fi
 
+ex_files=$(mktemp); echo $EXTRA_FILES > $ex_files
+
 sudo $spath/buildstrap $ARCH $DISTRO $TDIR $OUT_TMP \
 		"$(make_csv "$PACKAGES")"\
-		"$(echo "$EXTRA_FILES" | base64)" $INSTALL_BCC $SKIP_COMPRESS
+		$ex_files $INSTALL_BCC $SKIP_COMPRESS
+rm $ex_files
 
 # If we only wanted to prepare a rootfs and don't have
 # a device connected, then just echo that and skip cleanup