Add AddUnknownPattern() and AddMissingPattern().

The other activation functions can be used incrementally, but SetUnknownPatterns() and SetMissingPatterns() cannot. This makes it a bit annoying to use, since you can't have a wrapper function that either binds an attribute or add an unknown pattern, that you could for example call in a loop.

Since attribute patterns are just a vector anyway, it is easy to make it support incremental additions.

PiperOrigin-RevId: 748766532

Author: seirl

runtime/activation.h

@@ -92,10 +92,18 @@ class Activation final : public ActivationInterface {
   bool InsertOrAssignValueProvider(absl::string_view name,
                                    ValueProvider provider);
 
+  void AddUnknownPattern(cel::AttributePattern pattern) {
+    unknown_patterns_.push_back(std::move(pattern));
+  }
+
   void SetUnknownPatterns(std::vector<cel::AttributePattern> patterns) {
     unknown_patterns_ = std::move(patterns);
   }
 
+  void AddMissingPattern(cel::AttributePattern pattern) {
+    missing_patterns_.push_back(std::move(pattern));
+  }
+
   void SetMissingPatterns(std::vector<cel::AttributePattern> patterns) {
     missing_patterns_ = std::move(patterns);
   }