fix: conditionally disable defconfig check for android16-6.12

Update the GitHub Action for building the kernel to only disable the defconfig check in BUILD.bazel when the bypass input is not explicitly set to false. This ensures the check runs by default while allowing users to bypass it when needed.

.github/actions/build-kernel/action.yml

@@ -64,7 +64,9 @@ runs:
         HOSTLD="${{ github.workspace }}/kernel/common/ld-wrapper"
       else
         if [[ ${{ inputs.version }} == "android16-6.12" ]]; then
-          sed -i '/name = "kernel_aarch64",/a\    check_defconfig = "disabled",' common/BUILD.bazel
+          if [ "${{ inputs.bypass }}" = "false" ]; then
+            sed -i '/name = "kernel_aarch64",/a\    check_defconfig = "disabled",' common/BUILD.bazel
+          fi
           tools/bazel run \
             --config=fast \
             --config=stamp \