gbmcweb gbmc-release-26.6.x: SRCREV bump 4a5f7b8455..61ab52f

Edward Lee (4):
      Dont Promote OwnerVerificationCert in Credential Manager
      Enforce Firmware Updateable in tlBMC
      Install OVC in Staging Directory
      Stage the OVC Config in Dedicated Stage Folder

Nan Zhou (3):
      Disable Redfish Event Service functionality in gbmcweb.
      Check if eMMC is mounted before writing during multipart update.
      Clear /var/google/firmware_bundle/ before install.

gBMC Team (7):
      Bloom SSH access and OVC verification API changes
      Remove dead signature check code from PostInstall
      Block dev bundle installations through the owner configuration.
      Bloom install: Resolve command injection std::system issues
      Delete any files in the installation bundle directory that are not in the manifest.
      Update ParsePostInstallPackages to filter out unauthorized packages.
      Remove bundle signature and sums files before install

Google-Bug-Id: 496662818
Platforms-Affected: Bloom
Fusion-Link: fusion2 N/A
Tested: N/A
Change-Id: I1f8eb990e92e1853bcb25425f273c830962b77c2
Signed-off-by: Nan Zhou <nanzhou@google.com>