Run correctly no matter what directory the script is executed from

Signed-off-by: Eddie Ringle <eddie.ringle@gmail.com>
diff --git a/extract-google-files b/extract-google-files
index 3b760db..16cbcdb 100755
--- a/extract-google-files
+++ b/extract-google-files
@@ -1,5 +1,6 @@
 #!/bin/bash
 
+cd `dirname $0`
 mkdir -p proprietary
 
 adb pull /system/app/CarHomeGoogle.apk proprietary