Apply suggestions from code review

Co-authored-by: Pierre R. Mai <pmai@pmsf.de>
Signed-off-by: Clemens Linnhoff <clemens.linnhoff@persival.de>

Author: ClemensLinnhoff

osi_common.proto

@@ -235,7 +235,7 @@ message ExternalReference
 
     // The type of the external references.
     //
-    // Value describing the type of the original source.
+    // Mandatory value describing the type of the original source.
     //
     // For OpenX/ASAM standards it is specified as follows:
     // - net.asam.opendrive

osi_route.proto

@@ -42,7 +42,6 @@ message Route
     //
     // \rules
     // is_set
-    // is_globally_unique
     // \endrules
     //
     optional Identifier route_id = 1;

osi_trafficcommand.proto

@@ -144,7 +144,6 @@ message TrafficAction
         //
         // \rules
         // is_set
-        // is_globally_unique
         // \endrules
         //
         optional Identifier action_id = 1;