added new header for routing to desired database

Author: KIRTIKUMARKK21

grpc-context-utils/src/main/java/org/hypertrace/core/grpcutils/context/RequestContextConstants.java

@@ -12,6 +12,7 @@
 public class RequestContextConstants {
   public static final String TENANT_ID_HEADER_KEY = "x-tenant-id";
   public static final String REQUEST_ID_HEADER_KEY = "request-id";
+  public static final String DATABASE_ID_HEADER_KEY = "x-database-id";
 
   public static final Metadata.Key<String> TENANT_ID_METADATA_KEY =
       Metadata.Key.of(TENANT_ID_HEADER_KEY, ASCII_STRING_MARSHALLER);
@@ -27,12 +28,13 @@ public class RequestContextConstants {
           "traceparent",
           "tracestate",
           AUTHORIZATION_HEADER,
-          REQUEST_ID_HEADER_KEY);
+          REQUEST_ID_HEADER_KEY,
+          DATABASE_ID_HEADER_KEY);
 
   /**
    * These headers may affect returned results and should be accounted for in any cached remote
    * results
    */
   static final Set<String> CACHE_MEANINGFUL_HEADERS =
-      Set.of(TENANT_ID_HEADER_KEY, AUTHORIZATION_HEADER);
+      Set.of(TENANT_ID_HEADER_KEY, AUTHORIZATION_HEADER, DATABASE_ID_HEADER_KEY);
 }