crosvm: Fix apt-get command

[maflcko]

Using apt upgrade without -y is problematic, because it may fail:

Step #17: Step 3/4 : RUN apt-get upgrade && apt-get install --yes --no-install-recommends     libclang-dev     pkg-config     libcap-dev
Step #17:  ---> Running in 4fd961f9329f
Step #17: Reading package lists...
Step #17: Building dependency tree...
Step #17: Reading state information...
Step #17: Calculating upgrade...
Step #17: The following packages will be upgraded:
Step #17:   bsdutils fdisk libblkid1 libfdisk1 libmount1 libsmartcols1 libuuid1 mount
Step #17:   util-linux
Step #17: 9 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Step #17: Need to get 1901 kB of archives.
Step #17: After this operation, 4096 B of additional disk space will be used.
Step #17: Do you want to continue? [Y/n] Abort.
Step #17: The command '/bin/sh -c apt-get upgrade && apt-get install --yes --no-install-recommends     libclang-dev     pkg-config     libcap-dev' returned a non-zero code: 1
Finished Step #17
ERROR

Also, an apt-get update is needed, anyway.

Fix both issues by replacing upgrade with update.

[github-actions]

maflcko is a new contributor to projects/crosvm. The PR must be approved by known contributors before it can be merged. The past contributors are: denniskempin

[maflcko]

cc @denniskempin

[denniskempin]

Thank you for the fix!