Improve the check for being a package metadata rule

This allows the refactoring which will happen after default_applicable_licenses is renamed to default_package_metadata. The current behavior is intended to prevent
`applicable_licenses` from being set on a `license` rule. The required behavior is that we don't set `applicable_licenses` on any of the metadata rules.

Future changes might have to take into account the ability to set the license for a tool rule within `rules_package`.

For background, see https://docs.google.com/document/d/1uyJjkKbE8kV8EinakaR9q-Un25zCukhoH_dRBkWHSKQ/edit#heading=h.izpa22p82m6c

Closes bazelbuild#16596.

PiperOrigin-RevId: 485457037
Change-Id: Ifb105f646ae0c291a6841b3ddb84ed536e9d71e3

src/main/java/com/google/devtools/build/lib/packages/RuleClass.java

@@ -2735,6 +2735,14 @@ public boolean isPackageMetadataRule() {
       // not building it today because the exact needs are not clear.
       return true;
     }
+    // BEGIN-INTERNAL
+    // TODO(aiuto): This is a Google-ism, remove from Bazel.
+    String packageName = ruleDefinitionEnvironmentLabel.getPackageName();
+    if (packageName.startsWith("tools/build_defs/license")
+        || packageName.startsWith("third_party/rules_license")) {
+      return true;
+    }
+    // END-INTERNAL
     return false;
   }
 }