Add etc/hosts to backuptool.
diff --git a/prebuilt/common/bin/backuptool.sh b/prebuilt/common/bin/backuptool.sh
index 1f256bf..1c2cee1 100755
--- a/prebuilt/common/bin/backuptool.sh
+++ b/prebuilt/common/bin/backuptool.sh
@@ -68,6 +68,7 @@
 lib/libinterstitial.so
 lib/libspeech.so
 lib/libzxing.so
+etc/hosts
 EOF
 }