[ANNOUNCE] Re-spin of 4.15 kernels in proposed pocket

[Kleber Souza]

Due to LP: #1796542 ("Silent data corruption in Linux kernel 4.15"), we
are re-spinning all the 4.15 kernels of the current SRU cycle:

* Bionic:
  - linux, linux-raspi2, linux-aws, linux-gcp, linux-oem, linux-kvm,
    linux-azure
* Xenial:
  - linux-gcp, linux-hwe, linux-hwe-edge, linux-azure, linux-azure-edge
* Trusty:
  - linux-azure


Regards,
Kleber