absl/BUILD.bazel: Make license comment consistent with other bazel build files

PiperOrigin-RevId: 549965642
Change-Id: I708dd56a36d60cbc00564fa789e1cb1ef37f950a

Author: rickeylev

absl/BUILD.bazel

@@ -12,6 +12,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+#
 
 load("@bazel_skylib//lib:selects.bzl", "selects")