core: add getCallOptions() to CallCredentials.RequestInfo (#9538)

This is needed internally (b/134067789#comment20).

api/src/main/java/io/grpc/CallCredentials.java

@@ -91,6 +91,13 @@ public abstract class CallCredentials {
      */
     public abstract MethodDescriptor<?, ?> getMethodDescriptor();
 
+    /**
+     * The call options used to call this RPC.
+     */
+    public CallOptions getCallOptions() {
+      throw new UnsupportedOperationException("Not implemented");
+    }
+
     /**
      * The security level on the transport.
      */

core/src/main/java/io/grpc/internal/CallCredentialsApplyingTransportFactory.java

@@ -127,6 +127,11 @@ final class CallCredentialsApplyingTransportFactory implements ClientTransportFa
               return method;
             }
 
+            @Override
+            public CallOptions getCallOptions() {
+              return callOptions;
+            }
+
             @Override
             public SecurityLevel getSecurityLevel() {
               return firstNonNull(

core/src/test/java/io/grpc/internal/CallCredentialsApplyingTest.java

@@ -148,6 +148,7 @@ public class CallCredentialsApplyingTest {
     RequestInfo info = infoCaptor.getValue();
     assertSame(transportAttrs, info.getTransportAttrs());
     assertSame(method, info.getMethodDescriptor());
+    assertSame(callOptions, info.getCallOptions());
     assertSame(AUTHORITY, info.getAuthority());
     assertSame(SecurityLevel.NONE, info.getSecurityLevel());
   }