Remove ro.url.legal* props from proto

Not read/written anywhere.

Test: presubmit
Change-Id: I3f5a87c98c6438b7e6e61c92861eed1af195b3e7
diff --git a/core/proto/android/os/system_properties.proto b/core/proto/android/os/system_properties.proto
index 973fa5a..c9fef43 100644
--- a/core/proto/android/os/system_properties.proto
+++ b/core/proto/android/os/system_properties.proto
@@ -446,8 +446,7 @@
         }
         optional Telephony telephony = 38;
 
-        optional string url_legal = 39;
-        optional string url_legal_android_privacy = 40;
+        reserved 39, 40; // Removed url_legal* props
 
         message Vendor {
             optional string build_date = 1;