Disallow input file write access to jdigen.py am: 091ceb2bb2 am: e638766f63 am: 8352906c00

Original change: https://android-review.googlesource.com/c/platform/external/oj-libjdwp/+/1351023

Change-Id: I4233a5e5787b1234105e6b2b108b86a6268f62f5
diff --git a/etc/jdigen.py b/etc/jdigen.py
index a5ba1a5..d8ce8af 100644
--- a/etc/jdigen.py
+++ b/etc/jdigen.py
@@ -51,7 +51,7 @@
 INSTANCE_FORMAT = '{{ "{key}", "{value}" }},\n'
 
 VALUES = ""
-with open(args[1], 'r+') as inp:
+with open(args[1], 'r') as inp:
   for l in inp.readlines():
     key, value = l.split('=')
     VALUES += INSTANCE_FORMAT.format(key = key.strip(), value = value.strip())