ANDROID: Kleaf: common kernel public

.... so it can be referenced in mixed builds.

Test: build cuttlefish
Bug: 202075496
Change-Id: I8d79847c54c639fa619edf3280c021f02ba76645
Signed-off-by: Yifan Hong <elsk@google.com>
Signed-off-by: Matthias Maennich <maennich@google.com>

BUILD.bazel

@@ -11,6 +11,11 @@
 # 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.
+package(
+    default_visibility = [
+        "//visibility:public",
+    ],
+)
 
 load("//build/kleaf:common_kernels.bzl", "define_common_kernels")