Silence unpack-prebuilt-apex

Build tools should not output anything on success, as it clutters
the terminal.

Test: No
Change-Id: Iadfc326be58b32d5cb4f40dd114d3f0a54dbd9b4
diff --git a/scripts/unpack-prebuilt-apex.sh b/scripts/unpack-prebuilt-apex.sh
index 1acdeb5..f34a480 100755
--- a/scripts/unpack-prebuilt-apex.sh
+++ b/scripts/unpack-prebuilt-apex.sh
@@ -29,8 +29,6 @@
 shift 4
 REQUIRED_PATHS=$@
 
-set -x 1
-
 rm -fr $OUTPUT_DIR
 mkdir -p $OUTPUT_DIR