Update Skylark -> Starlark.

PiperOrigin-RevId: 399777947
diff --git a/rules/rules.bzl b/rules/rules.bzl
index 0d416ec..315fd4f 100644
--- a/rules/rules.bzl
+++ b/rules/rules.bzl
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-"""Skylark rules for building Android apps."""
+"""Starlark rules for building Android apps."""
 
 load(
     "//rules/aar_import:rule.bzl",